Forensic Entomology – Using Insects for Forensic Investigations

Forensic Entomology – Using Insects for Forensic Investigations

Introduction

Forensic Entomology plays a significant role in the investigation of deaths. It is a branch of forensic science that deals with the study of insects for forensic analysis.

What comes to your mind when you hear the word ‘insects’?

The unavoidable creepy, crawly creatures that have always been the patrons of hate and loathe, isn’t it? Insects have always been unwanted on the face of the planet, at least for plebeians like us.

But did you ever wonder why Forensic Scientists have a different level of regard altogether for insects?

These ubiquitous creepy-crawlies actually contain a profound source of vital information for forensic investigators probing serious cases such as murders, accidents, natural deaths, and sexual assaults.

So what is Forensic Entomology? And how are insects used in Forensic Entomology? You will find out in the following sections.

Forensic Entomology - Definition

Forensic Entomology is the application of zoological principles for gaining forensic insights. Study of insects and other arthropods found on and near a cadaver are crucial to estimating the post mortem interval. Post mortem interval i.e. the time that has elapsed since the death of a living being is vital in probing the death of humans and animals.

Post mortem interval is estimated by a scientific evaluation of the insects present at the scene and on the body. It also requires a thorough examination of the environment in which the corpse is found to study the succession patterns of the insects.

Forensic Entomology is particularly useful for conducting forensic investigations in legal and criminal cases. Although it is mostly applied for investigation of a death, it is also helpful in detection of drugs and poisons, determination of the location of an incident and estimation of the time of infliction of wounds.

History of Forensic Entomology

The first instance of insects’ use in Forensic Entomology was in ancient China when a local farmer was found hacked to death.

At a time when forensic science was still in its formative years, all that investigators had was an understanding of the basic principles of the science. This led to the investigators actually inflicting wounds from multiple weapons on an animal carcass.

On comparing the wound with the one on the victim it was conclusive that it was caused by a sickle. Since a sickle was most likely to be used by a peasant, the local magistrate asked all suspected local peasants to gather with their sickles.

The peasant who had assembled at the town square were asked to lay their sickles on the ground. While most stood unaware, the magistrate for sure knew what was in store for the spectators and the guilty!

Primitive Forensic Entomology

As the sickles lay on the ground, bright metallic green flies began gathering over the village square.

Eventually, they started swarming over one hand sickle in particular. This was sufficient for the peasant owning that sickle and the entire village to perceive who the guilty really was.

The metallic colored flies were blow flies that are naturally attracted to the soft tissues, blood, and bones of dead bodies. This was the very first case in the history of forensic science when forensic entomology was used to convict the guilty and serve justice.

Subsequently, forensic entomology and the way insects are used for investigations have evolved significantly lending deeper insights to forensic scientists.

Evolution of Forensic Entomology

Francesco Redi, an Italian physician, refuted the theory of spontaneous generation in 1668. At that time, the incumbent theory was that maggots developed spontaneously from a rotting piece of meat. However, Redi could prove through a series of experiments that it was only when meat was fully or partially exposed to air that it developed fly maggots.

The discovery that maggots did not develop on rotting meat that was not exposed to air brought huge revolution in the world of forensic entomology. It spurred further analysis of insect life cycles and forensic entomology as a whole.

Insects Used in Forensic Entomology

So here’s breaking the mystery. How can something as despicable as insects lend such crucial information to forensic investigators? The following section shall reveal how are insects used in forensic entomology.

Flies:

Flies are among the first insects that are attracted to a corpse. Their offspring, maggots, feed on moist cadavers. Following are the flies that are relevant to forensic entomology.

1.Blow Flies: Blow flies are the ones that have mentioned in the first record of the application of forensic entomology in Song Ci’s book. These metallic looking flies have the ability to smell decaying flesh from up to 16 km away. That’s called as having some real olfactory senses!!

2.Flesh Flies: Flesh flies mostly breed on decaying corpses, garbage, dung or any other decaying material. A few species, however, lay their eggs in the exposed wounds of mammals. Being viviparous in nature, flesh flies often give birth on decaying human and animal corpses.

3.House Flies: They are the most common type of flies and are the carriers of serious diseases as we are all aware!

4.Cheese Flies: These flies are mostly found in animal products and fungi. Their larvae most infest smoked fish, cured meat, cheese and decaying animals. The presence of cheese fly larvae is crucial for estimating the time of death for humans.

Beetles:

Beetles generally infest a corpse in the later stages of decomposition compared to flies. Beetles are replaced by moth flies in drier conditions.

*Dermestid Beetles: Also called as skin or hide beetles, they infest a decomposing cadaver only once the soft tissues have been devoured by other organisms. They thrive on the skin and hair and are one of the most common insects collected by forensic entomologists from human corpses.

*Bone Beetles: These are also collected from corpses in the later stages of decomposition. Beetles belonging to this family (Cleridae) feed on decaying flesh, leaving the skeletal remains immaculately clean!

*Carrion Beetles: The larva of carrion beetles are known to thrive on vertebrate carcasses while the adults devour maggots. These chaps are quite a patron of social service as they have a tendency to dig and inter small carcasses underground.

*Hide Beetles: These feed on decaying carcasses and dry animal products such as bacon, dog treats, dried fish, cheese, and They usually form clusters around resources where feeding and mating are likely to happen.

*Rove Beetles: Rove beetles are different from carrion beetles in a way that they feed on cadavers or carcasses and not on decaying flesh (carrion). They thrive on maggots and other insect larvae present on carrions.

*Scarab Beetles: Scarab beetles belong to the Scarabaeidae family that also includes dung beetles which are generally found on or under carrion and corpses. They feed on fungi, dung or decaying flesh and act as a cleanup crew for the animal kingdom.

*Sap Beetles: These beetles are mostly found near fermenting or decaying plant fluids such as rotting melons or tree sap. Some sap beetles though infest carcasses also and are very crucial in forensic entomology.

*Clown Beetles: Also known as Hister beetles, these beetles are smart players. They usually hide under the carcass during the day to emerge at night and feed on maggots or dermestid beetle larvae thriving on it.

*Dung Beetles: These beetles thrive and feed on carrion. Their larvae feed on decaying fungi, manure and vertebrate carcasses at any stage of the decomposition.

*Mites: Macrocheles mites feed on carcasses in the early stages of the decomposition whereas Tyroglyphidae and Oribatidae mites thrive on dry skin later in the decomposition process.

*Moths: The larvae of moths that are active primarily during twilight and daytime feed on the hair of mammalian corpses and are amongst the last animals joining in the decomposition of a corpse.

Application of Forensic Entomology for Investigations Other than Death

#Food Infestation Cases: Food production facilities where Integrated Pest Management procedures are not followed can be quite enticing for pests. Cases involving the contamination of food products with insect debris call for the involvement of a forensic entomologist to investigate and provide litigation support.

#Presence of Drugs: An analysis of the bodies, feces and dead skins of insects feeding on carrion and cadavers helps forensic entomologist determine the presence and type of drugs or poison in the body.

#DNA Extraction: Blood-sucking insects consume blood that makes it possible for a forensic scientist to use it for extraction of DNA. This is helpful in cases where the assailant leaves a bite-mark evidence.

Haemophilia

Haemophilia 

Key facts

#Haemophilia is an inherited bleeding disorder, which means it can be passed on from birth parents to their children.

#If you have haemophilia, your blood doesn’t clot properly, which makes it difficult to control bleeding.

#Some people have mild haemophilia, while others are more severely affected.

#The main symptoms of haemophilia are easy bruising, having large bruises, and greater than normal bleeding from surgery or menstruation.

#There is no cure for haemophilia, but heavy bleeding can be controlled with medical treatment.

Introduction

Haemophilia is an inherited bleeding disorder, which means it can be passed on from birth parents to their children. If you have haemophilia, your blood doesn’t clot properly. This can lead to bleeding that is difficult to control.

When a blood vessel is injured, special proteins in the blood called ‘clotting factors’ act to control blood loss by plugging or patching up the injury. People with haemophilia have lower than normal levels of a clotting factor.

Types of Haemophilia

There are 2 types of haemophilia.

1.Haemophilia A (also called classic haemophilia) is the most common type. It is caused by a lack of clotting factor 8.

2.Haemophilia B (sometimes called Christmas disease) is caused by a lack of clotting factor 9.

It is important to know the type of haemophilia you have, as each type requires different clotting factor treatment.

Some people have mild haemophilia, while others are more severely affected.

Symptoms of Haemophilia

The main signs of haemophilia are:

*Easy bruising from an early age.

*Internal bleeding for no obvious reason, especially in the joints and muscles.

*Greater than normal bleeding following injury or surgery.

*Abnormally heavy bleeding during menstruation or after giving birth.

Although bleeding problems often start from a very young age, some children don’t have symptoms until they begin walking or running. People with mild haemophilia may not bleed excessively until they get an injury or have surgery.

Causes of Haemophilia

Haemophilia is an inherited condition and occurs in families, but 1 in 3 people with haemophilia will have it even without a family history of the disorder.

Haemophilia is caused by a mutation in a gene that is located on the X chromosome.

Females have 2 copies of the X chromosome in body cells, while males have one X chromosome and one Y chromosome. For this reason, haemophilia is much more common in males. Females who inherit a gene for haemophilia often have an unaffected gene on their other X chromosome. This means that they while they can pass on the gene for haemophilia to their children (be a genetic carrier), they may not be affected by haemophilia themselves.

Causes of Haemophilia

Diagnosis

If your doctor suspects that you have haemophilia, they may refer you for blood tests to measure the levels of clotting factors in your blood. These tests can show the type and severity of the disease.

Genetic testing can often confirm a diagnosis of haemophilia, but in some cases, doctors won’t know if you have a gene mutation.

Treatment

There is currently no cure for haemophilia. It is possible to manage haemophilia effectively, although it can be complex.

When someone with haemophilia has a bleeding episode, they will need treatment to help their blood clot and stop the bleeding. This usually involves giving clotting factors by infusion or injection.

If you have haemophilia, you need to be very careful not to injure yourself. Be sure to learn how to recognise a bleed, as there may be no visible signs of bleeding, for example, if your bleed inside your body.

Australian guidelines recommend that people with haemophilia get care from a team of healthcare professionals. This team may include doctors (GPs and/or specialists) nurses, medical scientists, physiotherapists, social workers and psychologists.

If you are diagnosed with haemophilia, you should ask your doctor about the benefits of referral to a haemophilia treatment centre, where a health team can provide you with comprehensive care.

Complications of Haemophilia

The most common complication of the haemophilia is damage to joints and muscles that result from bleeding into these areas. These complications are best managed by a multidisciplinary health care team.

Phobias

Phobias

Introduction

Phobias are an intense fear of something, like heights or certain animals, that causes significant distress. They’re typically treated with therapy, medication, or a combination of both.

A phobia is an irrational fear of something that’s unlikely to cause harm. The word itself comes from the Greek word“phobos,” which means “fear” or “horror.”

Hydrophobia, for example, literally translates to fear of water.

When someone has a phobia, they experience intense fear of a certain object or situation. Phobias are different from regular fears because they cause significant distress, possibly interfering with life at home, work, or school.

People with phobias actively avoid the phobic object or situation, or they endure it with intense fear or anxiety.

Agoraphobia, a fear of places or situations that trigger fear or helplessness, is singled out as a particularly common fear with its own unique diagnosis. Social phobias, which are fears related to social situations, are also singled out with a unique diagnosis.

Phobias come in all shapes and sizes. Because there are an infinite number of objects and situations, the list of specific phobias is quite long.

Types of phobias

According to the DSM-5, specific phobias typically fall within five general categories:

*Fears related to animals (spiders, dogs, insects)

*Fears related to the natural environment (heights, thunder, darkness)

*Fears related to blood, injury, or medical issues (injections, broken bones, falls)

*Fears related to specific situations (flying, riding an elevator, driving)

*Other (fear of choking, loud noises, drowning)

These categories encompass an infinite number of specific objects and situations.

There’s no official list of phobias beyond what’s outlined in the DSM-5, so clinicians and researchers create names for them as the need arises. This is typically done by combining a Greek (or sometimes Latin) prefix that describes the phobia with the –phobia suffix.

For example, a fear of water would be named by combining “hydro” (water) and “phobia” (fear).

There’s also such a thing as a fear of fears (phobophobia). This is actually more common than you might imagine.

People with anxiety disorders sometimes experience panic attacks when they’re in certain situations. These panic attacks can be so uncomfortable that people do everything they can to avoid them in the future.

For example, if you have a panic attack while sailing, you may fear sailing in the future, but you may also fear panic attacks or fear developing hydrophobia.

List of phobias

Studying specific phobias is a complicated process. Most people don’t seek treatment for these conditions, so cases largely go unreported.

These phobias also vary based on cultural experiences, gender, and age.

Here’s a look at some phobias that have been identified.

1.Achluophobia - Fear of darkness

2.Acrophobia - Fear of heights

3.Aerophobia - Fear of flying

4.Agoraphobia - Fear of public spaces or crowds

5.Aichmophobia - Fear of needles or pointed objects

6.Ailurophobia - Fear of cats

7.Alektorophobia - Fear of chickens

8.Algophobia - Fear of pain

9.Amaxophobia - Fear of riding in a car

10.Androphobia - Fear of men

11.Anginophobia - Fear of angina or choking

12.Anthophobia - Fear of flowers

13.Anthropophobia - Fear of people or society

14.Aphenphosmphobia - Fear of being touched

15.Arachnophobia - Fear of spiders

16.Arithmophobia - Fear of numbers

17.Astraphobia - Fear of thunder and lightning

18.Ataxophobia - Fear of disorder or untidiness

19.Atelophobia - Fear of imperfection

20.Atychiphobia - Fear of failure

21.Autophobia - Fear of being alone

22.Bacteriophobia - Fear of bacteria

23.Barophobia - Fear of gravity

24.Bathmophobia - Fear of stairs or steep slopes

25.Batrachophobia - Fear of amphibians

26.Belonephobia - Fear of pins and needles

27.Bibliophobia - Fear of books

28.Botanophobia - Fear of plants

29.Cacophobia - Fear of ugliness

30.Catagelophobia - Fear of being ridiculed

31.Catoptrophobia - Fear of mirrors

32.Chionophobia - Fear of snow

33.Chromophobia - Fear of colors

34.Chronomentrophobia - Fear of clocks

35.Cibophobia - Fear of food

36.Claustrophobia - Fear of confined spaces

37.Coulrophobia - Fear of clowns

38.Cyberphobia - Fear of computers

39.Cynophobia - Fear of dogs

40.Dendrophobia - Fear of trees

41.Dentophobia - Fear of dentists

42.Domatophobia - Fear of houses

43.Dystychiphobia - Fear of accidents

44.Emetophobia - Fear of vomiting

45.Entomophobia - Fear of insects

46.Ephebiphobia - Fear of teenagers

47.Equinophobia - Fear of horses

48.Gamophobia - Fear of marriage or commitment

49.Genuphobia - Fear of knees

50.Glossophobia - Fear of speaking in public

51.Gynophobia - Fear of women

52.Heliophobia - Fear of the sun

53.Hemophobia - Fear of blood

54.Herpetophobia - Fear of reptiles

55.Hydrophobia - Fear of water

56.Hypochondria - Fear of illness

57.Iatrophobia - Fear of doctors

58.Insectophobia - Fear of insects

59.Koinoniphobia - Fear of rooms full of people

60.Leukophobia - Fear of the color white

61.Lilapsophobia - Fear of tornadoes and hurricanes

62.Lockiophobia - Fear of childbirth

63.Mageirocophobia - Fear of cooking

64.Megalophobia - Fear of large things

65.Melanophobia - Fear of the color black

66.Microphobia - Fear of small things

67.Mysophobia - Fear of dirt and germs

68.Necrophobia - Fear of death or dead things

69.Noctiphobia - Fear of the night

70.Nosocomephobia - Fear of hospitals

71.Nyctophobia - Fear of the dark

72.Obesophobia - Fear of gaining weight

73.Octophobia - Fear of the number 8

74.Ombrophobia - Fear of rain

75.Ophidiophobia - Fear of snakes

76.Ornithophobia - Fear of birds

77.Papyrophobia - Fear of paper

78.Paruresis - Fear of urinating in public places or in the presence of others

79.Pathophobia - Fear of disease

80.Pedophobia - Fear of children

81.Philophobia - Fear of love

82.Phobophobia - Fear of phobias

83.Podophobia - Fear of feet

84.Pogonophobia - Fear of beards

85.Porphyrophobia - Fear of the color purple

86.Pteridophobia - Fear of ferns

87.Pteromerhanophobia - Fear of flying

88.Pyrophobia - Fear of fire

89.Samhainophobia - Fear of Halloween

90.Scolionophobia - Fear of school

91.Selenophobia - Fear of the moon

92.Sociophobia - Fear of social evaluation

93.Somniphobia - Fear of sleep

94.Tachophobia - Fear of speed

95.Technophobia - Fear of technology

96.Thalassophobia - Fear of deep water

97.Tonitrophobia - Fear of thunder

98.Trypanophobia - Fear of needles or injections

99.Trypophobia - Fear of clustered patterns of holes

100.Venustraphobia - Fear of beautiful women

101.Verminophobia - Fear of germs

102.Wiccaphobia - Fear of witches and witchcraft

103.Xenophobia - Fear of strangers or foreigners

104.Zoophobia - Fear of animals

Treating a phobia

Phobias are typically treated with therapy, medication, or a combination of both:

Exposure therapy. During exposure therapy, which is a type of cognitive behavioral therapy, you work with a psychologist to learn how to desensitize yourself to the object or situation that you fear. The goal is to improve your quality of life so that you’re no longer hindered or distressed by your fear.

Antianxiety medication. Your doctor may recommend certain anxiety-reducing medications that can help you through exposure therapy. While these medications aren’t exactly a treatment for phobias, they can help make exposure therapy less distressing.

Other medications. Your clinician might also prescribe beta-blockers and benzodiazepines to manage feelings of anxiety or panic.

The Takeaway

Phobias are persistent, intense, and unrealistic fears of a certain object or situation. Specific phobias are related to certain objects and situations. They typically involve fears related to animals, natural environments, medical issues, or specific situations.

While phobias can be extremely uncomfortable and challenging, therapy and medication can help. If you think you may have a phobia that’s causing a disruption in your life, speak with your doctor for an evaluation and treatment options.

Trephination

Trephination

Introduction:

Trephination, also known as trepanning, trepanation or burr holing, is one of the oldest surgical procedures known to humanity and refers to a surgical procedure in which a circular piece of bone is drilled and excised, most commonly from the human skull. While the term trephination typically refers to the creation of a hole in the skull, there are other uses of trephination, such as in the fingernail or toenail. 

Trephination of the skull can be performed while the person is living or dead (i.e., postmortem). It has been performed in many areas of the world and throughout history, spanning from Mesolithic (i.e., prehistoric) to modern times. 

Today, there are four techniques that can be used for trephination: drilling using a trephine (i.e., surgical instrument with a cylindrical blade) or drill, scraping using an abrasive instrument, cutting using an incisive instrument, or boring and cutting using a drill and an incisive instrument. Complications that may arise during trephination include brain injury, hemorrhage, and infection. 

Trephination Uses:

Throughout history, trephination has been a medical technique used to relieve intracranial pressure and headaches. In the fifth century BCE, physicians practicing under the guidance of Hippocrates believed that stagnant blood, like stagnant water, could decay and turn into pus (i.e., liquid produced in infected tissue). For that reason, trephining allowed blood to flow out before it spoiled. This eventually fell out of practice due to low survival rates and infection. 

At the end of the 19th century, physicians learned about the importance of modern antisepsis and infection prophylaxis, and understood the importance of intracerebral pressure in head injury. 

This allowed trephination to return as a surgical therapy for the treatment and management of head trauma, including fractured skulls, head wounds, intracranial hemorrhage, intracranial disorders, chronic headache, brain tumors, and other painful skull disorders. 

Trephining is no longer used for therapeutic purposes in itself, but is typically used for exploratory diagnosis, relieving intracranial pressure due to epidural or subdural hematoma, debriding a penetrating head wound, and gaining access to the brain. 

In modern practice, the technique of drilling a hole in one’s skull is more commonly known as a craniotomy. In this procedure, a surgeon removes a piece of the skull to access the brain in order to treat conditions such as brain lesions and brain tumors. 

After treatment, the piece of skull is then replaced as soon as possible. It is important that, in the process of trephination, surgeons are careful to avoid penetration of the dura mater, which is the outer layer of connective tissue that protects the brain. If the dura mater is damaged, this could result in infection and physical damage to the underlying blood vessels, meninges, and brain tissue.

In 1884, frontal sinus trephination for the treatment of frontal sinus disease was described by physician Alexander Ogston. The technique had a high failure rate from complications of nasofrontal duct stenosis, or blockage of a duct that drains the sinuses. 

In the 1980s, endoscopic sinus surgery became the standard of care for the surgical management of frontal sinus disease. During this procedure, an endoscope (i.e., a camera on the end of a thin tool) is inserted into the nose to open the drainage pathways of the sinuses and restore their function. 

While endoscopy is still the standard of care to date, trephination may be used in cases of frontal sinus disease that are unable to be treated by endoscopy. For example, trephination is used if the surgeon needs an additional port for dissection, if the surgeon needs to rapidly decompress the frontal sinus, or if there is a tumor that has to be resected but cannot be done by endoscopy. 

Frontal sinus trephination is performed under local or general anesthesia. In the case of frontal sinus disease, trephination is used to relieve the pressure of the frontal sinus and drain the inflammatory cells and fluid. Following trephination, intravenous antibiotics are then administered to limit potential infection. 

In addition to treating frontal sinus disease, trephination has been used in the eye for corneal transplant and to treat glaucoma. Glaucoma is a condition in which the outflow of aqueous fluid of the eye is blocked, and intraocular pressure, or pressure within the eye, builds up. 

A procedure known as corneoscleral trephination has been documented in the treatment of glaucoma and consists of using a 1-2mm blade and topical anesthetic to relieve pressure of the eye. 

Lastly, while trephination mainly refers to the process of creating a hole in the human skull, the process of creating a hole in the fingernail or toenail is also referred to as trephination. Trephination of the nail is used as a procedure for subungual hematomas (i.e., blood under the nail). 

Subungual hematomas can occur from trauma, such as crushing one’s finger in a door or stubbing one's toe. Typically, an electric cautery tool is used to melt a hole through the nail and drain the blood from under the nail. Clinicians may also choose to use a needle and rotate it back and forth with slight downward pressure until dark blood is noted, being careful to not damage the nail bed. 

Important facts:

Trephination refers to the process of creating a hole in the skull and, in specific cases, the nail and is one of the oldest surgical procedures documented to date. It has been used throughout history with the goal of relieving pressure; managing symptoms of head trauma, such as subdural and epidural hematomas; and accessing brain tumors. 

Trephination can be performed using a trephine, a drill, by scraping with an abrasive instrument, or cutting with an incisive instrument. Common complications that may arise with trephination include infection and, if the dura mater surrounding the brain is damaged in the process, damage to the underlying blood vessels, meninges, and brain. Modern medicine has used trephination as part of treatments for frontal sinus disease, glaucoma, and subungual hematomas. 

Myopia

Myopia

Introduction

The structure of your eye is to blame. When your eyeball is too long or the cornea -- the protective outer layer of your eye -- is too curved, the light that enters your eye won’t focus correctly. Images focus in front of the retina, the light-sensitive part of your eye, instead of directly on the retina. This causes blurred vision. Doctors call this a refractive error.

High myopia: It’s a more serious form of the condition, where the eyeball grows more than it is supposed to and becomes very long front to back. Besides making it hard to see things at a distance, it can also raise your chance of having other conditions like a detached retina, cataracts, and glaucoma.

Degenerative myopia: Also called pathological or malignant myopia, it is a rare type you usually inherit from your parents. Your eyeball gets longer very quickly and causes severe myopia, usually by the teenage or early adult years. This type of myopia can get worse far into adulthood. Besides making it hard to see things at a distance, you may have a higher chance of having a detached retina, abnormal blood vessel growth in the eye (choroid neovascularization), and glaucoma.

Symptoms

Chances are the only symptom is that more distant objects are blurred. You may also notice:

Headaches

Squinting

Eye strain

Eye fatigue when you try to see objects more than a few Feet away

Children with myopia often have trouble reading the blackboard at school.

Diagnosis and Treatment

An eye exam can show you if you’re myopic. Glasses, contacts, or refractive surgery can usually correct the problem.

When you have myopia, your prescription for glasses or contact lenses will be a negative number. The more negative the number, the stronger your lenses will be. For example, -3.00 is stronger than -2.50.

Your prescription helps the eye focus light on your retina. That clears up your vision.

Eye surgery can improve your vision so much you may no longer need to wear glasses or contacts. The most common procedures for myopia are:

Photorefractive keratectomy: Also called PRK, this surgery uses a laser to sculpt the middle layer of your cornea. That flattens the cornea’s curve and lets light rays focus closer to or on your retina.

LASIK: This is the most common surgery for myopia. The surgeon uses a laser or another tool to create a thin flap on the top layer of your cornea. They sculpt the cornea with another laser and move the flap back into place.

EVO Implantable Collamer Lens (ICL): Using a microscopic incision, a contact lens made of a soft, polmeric materialis implanted into your eye between you natural lens and your iris. It helps refract light on the retina, producing clearer vision.

In the case of high myopia, special contacts or atropine eyedrops have been found to be effective in slowing the progression. In some cases, your doctor may suggest cataract or clear lens replacement surgery. 

Does It Get Better Over Time?

Myopia runs in families and will probably start in childhood. Multifocal lens (glasses or contacts) and eye drops such as atropine, pirenzepine gel, or cyclopentolate can help slow the progression. Your eyes usually stops changing after your teenage years, but not always. The incidents of myopia have been rising at an alarming rate in recent years. If you notice changes in your vision, get your eyes checked. See your eye doctor every year.

Optics of Myopia

Before discussing Optics of Myopia we should ratify parishioner phrase in Myopia. Briefly, the uncorrected myopia or nearsighted person. Usually can see up close better than far away. Hence, the term “nearsighted” make sense.

Derived from two Greek root words from myein “to shut” – ops “eye”.

Myopia is the refractive state of the eye in which with normal tonic accommodation, the parallel rays of light are brought to a focus on a point in front of the retinal plane when the eye is at rest.

In myopia the eyeball is usually deformed ; the deformation occurs at the posterior part of the globe only ,the anterior part is normal. The eyeball is usually large and looks prominent. When adducted the equator can be seen.

Refractive Error Definition 

A refractive error is a very common eye disorder . It exists when the rays of light do not focus on the retina means the eye cannot clearly focus the images from the outside world .

The eye’s optical system is to powerful over converging light in front of the retina . ( Myopia/Nearsighted)

The result of refractive errors is blurred vision, double vision , haziness or eye strain . which is sometimes so severe that it causes visual impairment .

Optics of Myopia: In myopes a near object may be focused without any effort of accommodation if it is situated at the punctum remotum . The image on the retina of an object at infinity is made up of circles of diffusion formed by divergent beam. 

In view of the absence of sharp focus the distant objects appear blurred. The nodal point in myopes is farther away from the retina and the image formed is larger in size which partly compensates for the blur due to absence of sharp focus . 

Accommodation is of little value to myopes, as any exercise of accommodation would only accentuate his visual problem . It would neither increase his vision nor reduce his myopia . In higher errors of refraction the amplitude of accommodation is small. 

The patient has no incentive to improve it and convergence does not get an accommodative influence . All these factors result in fatigue of accommodation and eye strain. Due to dissociation of convergence and accommodation exophoria commonly occurs and this may ultimately break into exotropia.

The eye of simple myopia is large and prominent. The Anterior chamber is deeper than normal and the pupil reacts sluggishly to light. The macula is slightly nearer to the disc than in a normal eye . 

The visual axis gets so altered that in some cases the angle alpha becomes slightly negative which gives an impression of a convergent squint . In myopia more commonly one sees a divergent strabismus.

Optical System 

The optical system is too powerful for it’s axial length , over converging light in front of the retina ( myopia / nearsighted).

Image of Distant Object 

Image of distant object on retina is made up of circle of diffusion formed by divergent beam since the parallel rays of light coming from the infinity are focused in front of the retina.

Far Point of the Myopic Eye : Far point is finite point in front of eye . The far point of myopic eye is 70 cm.

Nodal Point : Nodal point is further away from retina . The nodal point of human eye is located 17 mm in front of the retina.

Accommodation : Accommodation in uncorrected myopes is not developed normally , they may suffer from convergence insufficiency , exophoria and early presbyopia as they grow.

Image Formation: In myopia image formed in front of eye which is corrected by placing the negative lenses .

Optical Treatment : Include prescription of appropriate concave lens minimum acceptance providing maximum vision should be prescribed .

Never Overcorrected myopia

Guidelines For Correcting Low Degree Of Myopia Upto-6D :

Children younger than 8yrs should be fully corrected and instructed to use their glasses constantly.

Adult younger than 30 years :

Usually accept their full correction .

Older than 30 years :

Not able to tolerate a full correction with which the patient feels comfortable .

Prescribe less than full correction with which the patient feels comfortable.

Fossil Formation

Fossil Formation 

Introduction

A fossil is the mineralized partial or complete form of an organism, or of an organism’s activity, that has been preserved as a cast, impression or mold. A fossil gives tangible, physical evidence of ancient life and has provided the basis of the theory of evolution in the absence of preserved soft tissues.

The root of the word fossil derives from the Latin verb ‘to dig’ (fodere). A preserved inorganic object is not a fossil. The same applies to the mummification, desiccation and freezing of organisms, as mineralization is not a characteristic feature of these processes.Fossil form depends on the material in which it is preserved, and the ancient environment. Fossils can also represent organism movement and activity in the form of footprints and boring holes. An insect trapped in amber is a fossil subtype known as an inclusion; the originally soft, gum-like coniferous tree resin has fossilized into stone-like amber with the chitinous skeleton of the insect inside preserved, as shown below.

The oldest human fossil, where human refers to Homo erectus, Homo ergaster, and Homo georgicus, was a set of five skulls found in Dmanisi in Georgia between 1999 and 2005. These date back to approximately 1.8 million years ago. The oldest fossil remains depict five different species of microbe, preserved in a 3.5-billion-year-old rock in Australia. These microbes were carbon-dated by researchers at UCLA and the University of Wisconsin-Madison.

Types of Fossils

Fossil types are grouped according to the process in which they are formed, or to the evidence they have left behind. The method by which fossils are formed is termed as fossilization. Optimal conditions for fossilization are that an organism is buried very soon after its death and in the absence of bacterial or fungal decay, that mineral-rich waters and sediments surround the site, and the immediate environment is cool and hypoxic.

Compressions

Compressions are the most common fossil form, especially in plants, where some or the entire original organism is left behind as an imprint as the organism is slowly compressed between sediment layers. This means compression fossils are often distorted. Coal, a fossil fuel, is an example of a compression, where the combination of fallen vegetation on hypoxic swampland formed a sludge which was slowly compressed under the vertical pressures of swampland silts, and over a course of approximately 300 million years. Coal, a source of fossil fuel energy, is therefore far from a renewable source.

A sub-genre of the compression fossil is the compaction fossil. Compactions have less flattening and distortion, and a three-dimensional form is partially observable. Compactions are rare among crustaceans, as the hardest tissue (the shell or exoskeleton) is not supported by internal structures, leading to collapse and a compressed fossil. In larger, more complex organisms, soft tissues are usually unable to support the skeleton, and therefore the fossil forms are more likely to be compressions than compactions. Compactions of plant forms are more commonly found, but the famous Archaeopteryx bavarica shown below is a good example where some slight three-dimensional structure can still be observed.

Petrifactions

Petrified remains are the result of the replacement of the original remains with very specific minerals, which must be present in sufficient quantities dissolved in the water source. Petrification is an older term and rarely used except at certain tourist sites. The process by which the organism’s components are replaced by water-soluble minerals is called mineralization. These minerals are most commonly calcium carbonate, silicon dioxide, iron sulfide, iron carbonate and calcium phosphate. As the tissue of the dead, buried organism dissolves, the gaps left behind allow these minerals to seep in. Soft tissues are generally less well preserved than the petrifaction (or petrification) of hard tissues, depending on the environment and the rate of the replacement process. Petrified forests, like the one in Arizona shown below, contain stone-like tree stumps, the result of original tissue being replaced with crystalized minerals.

Casts and Molds

When dead organisms from earlier geologic eras are rapidly buried in sand, clay or silt sediments, the soft tissues decay, but harder tissues such as shells, carapaces, teeth and bones require a much longer period to dissolve.

A mold fossil is the equivalent of a plaster cast mold of a wax model. If an organism becomes trapped in sediment, decomposition takes place at an extremely slow rate as the sediment dries out and becomes rock. When the rock is cracked open millions of years later, the impression of the organism can be seen outlined in the rock, as in the shell featured below.

A cast fossil is the equivalent of liquid porcelain poured into a plaster-cast mold. Once dry, the mold can be removed and a porcelain version of the original wax model is the result. To become a cast, mineralization of the slowly decomposing organism is necessary. This process is the same as petrification, but in this case is named according to the fossil form. A cast always has a mold, although these can become lost over millennia. This cast of a giant whelk clearly shows its morphology in three dimensions.

Chemical Fossils or Chemofossils

Sometimes it is only chemicals that are left behind, as in the case of carbonization where all other chemical traces slowly disappear, leaving a thin layer of carbon. This phenomenon is known as a carbon film fossil or phytoleim and looks like a careful black or brown tracing of the original organism in two dimensions. Carbon films usually occur at the same time as compression, leaving a fine carbon print on the surface of a rock. In fact, any organic molecules left behind that prove the existence of past life are considered to be chemical fossils.

Traces, Tracks and Trails

Trace fossils, also called ichnofossils, tell us about an organism’s behavior rather than representing its anatomical form. Traces are split into four sub-groups – tracks, trails, coprolites, and gastroliths. Tracks are footprints, paw prints or claw prints which become covered with sediment before they are washed away by rain or wave. Trails are not usually made by feet, but by tentacles, the crawling patterns of snakes and worms, or the boreholes of prehistoric beetles. The picture below features a Tyrannosaurus rex track.

There are two other classes of trace fossils; coprolites and gastroliths. The first represents fossilized feces which usually contain difficult to digest remnants of a meal. Coprolites are usually petrified, or cast and mold fossils. Gastroliths are stones swallowed by certain animals to aid digestion.

How are Fossils Formed?

As already mentioned, the ideal conditions for fossilization are immediate burial in hypoxic, mineral-rich sediments in a low temperature environment. These elements make the existence of fossils rare. Four types of process contribute to the formation of a fossil. These are mineralization, carbonization, encrustation and distillation. They occur once an organism has become trapped within the surrounding sediment, and primarily depend on the mineral composition of silt and water.

Mineralization

Mineralization is the most common process in fossilization. Water within the sediment contains minerals that, over time, slowly replace the tissues of the original living organism. The most prevalent minerals that contribute to the fossilization process are calcium carbonate, iron sulfide, iron carbonate, calcium phosphate, and silica (silicon, silicon dioxide or quartz).

Carbonization and Distillation

The initiation of carbonization requires a certain type of bacteria that creates an anaerobic environment devoid of any oxygen or nitrogen. This bacteria turns plant life into carbon. Under millions of years of vertical compression, these ancient carbon fields become coal deposits. Distillation describes the process by which carbon film or phytoleim fossils are formed. This is an extremely rare occurrence, but can give a fine image of soft tissues. Fossils obtained by distillation are usually badly preserved, although significant external detail is possible.

Encrustation

Encrustation occurs in the presence of minerals – usually calcium carbonate – deposited in various layers on top of the remains of an organism. As tides rise and fall or water levels fluctuate, minerals slowly form a mold. While mineralization replaces organic matter, encrustation covers it. Mineralization will form a cast, encrustation the mold.

Rheumatoid Arthritis

Rheumatoid Arthritis 

Introduction

Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease, which means that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body.

RA mainly attacks the joints, usually many joints at once. RA commonly affects joints in the hands, wrists, and knees. In a joint with RA, the lining of the joint becomes inflamed, causing damage to joint tissue. This tissue damage can cause long-lasting or chronic pain, unsteadiness (lack of balance), and deformity (misshapenness).

RA can also affect other tissues throughout the body and cause problems in organs such as the lungs, heart, and eyes.

Signs and Symptoms

With RA, there are times when symptoms get worse, known as flares, and times when symptoms get better, known as remission.

Signs and symptoms of RA include:

Pain or aching in more than one joint.

Stiffness in more than one joint.

Tenderness and swelling in more than one joint.

The same symptoms on both sides of the body (such as in both hands or both knees).

Weight loss.

Fever.

Fatigue or tiredness.

Weakness.

Causes

RA is the result of an immune response in which the body’s immune system attacks its own healthy cells. The specific causes of RA are unknown, but some factors can increase the risk of developing the disease.

Risk factors

Researchers have studied a number of genetic and environmental factors to determine if they change person’s risk of developing RA.

Characteristics that increase risk

Age. RA can begin at any age, but the likelihood increases with age. The onset of RA is highest among adults in their sixties.

Sex. New cases of RA are typically two-to-three times higher in women than men.

Genetics/inherited traits. People born with specific genes are more likely to develop RA. These genes, called HLA (human leukocyte antigen) class II genotypes, can also make your arthritis worse. The risk of RA may be highest when people with these genes are exposed to environmental factors like smoking or when a person is obese.

Smoking. Multiple studies show that cigarette smoking increases a person’s risk of developing RA and can make the disease worse.

History of live births. Women who have never given birth may be at greater risk of developing RA.

Early Life Exposures. Some early life exposures may increase risk of developing RA in adulthood. For example, one study found that children whose mothers smoked had double the risk of developing RA as adults. Children of lower income parents are at increased risk of developing RA as adults.

Obesity. Being obese can increase the risk of developing RA. Studies examining the role of obesity also found that the more overweight a person was, the higher his or her risk of developing RA became.

Characteristics that can decrease risk

Unlike the risk factors above which may increase risk of developing RA, at least one characteristic may decrease risk of developing RA.

Breastfeeding. Women who have breastfed their infants have a decreased risk of developing RA.

Diagnosis

RA is diagnosed by reviewing symptoms, conducting a physical examination, and doing X-rays and lab tests. It’s best to diagnose RA early—within 6 months of the onset of symptoms—so that people with the disease can begin treatment to slow or stop disease progression (for example, damage to joints). Diagnosis and effective treatments, particularly treatment to suppress or control inflammation, can help reduce the damaging effects of RA.

Treatment 

RA can be effectively treated and managed with medication(s) and self-management strategies. Treatment for RA usually includes the use of medications that slow disease and prevent joint deformity, called disease-modifying antirheumatic drugs (DMARDs); biological response modifiers (biologicals) are medications that are an effective second-line treatment. In addition to medications, people can manage their RA with self-management strategies proven to reduce pain and disability, allowing them to pursue the activities important to them. People with RA can relieve pain and improve joint function by learning to use five simple and effective arthritis management strategies.

Complications

Rheumatoid arthritis (RA) has many physical and social consequences and can lower quality of life. It can cause pain, disability, and premature death.

Premature heart disease. People with RA are also at a higher risk for developing other chronic diseases such as heart disease and diabetes. To prevent people with RA from developing heart disease, treatment of RA also focuses on reducing heart disease risk factors. For example, doctors will advise patients with RA to stop smoking and lose weight.

Obesity. People with RA who are obese have an increased risk of developing heart disease risk factors such as high blood pressure and high cholesterol. Being obese also increases risk of developing chronic conditions such as heart disease and diabetes. Finally, people with RA who are obese experience fewer benefits from their medical treatment compared with those with RA who are not obese.

Employment. RA can make work difficult. Adults with RA are less likely to be employed than those who do not have RA. As the disease gets worse, many people with RA find they cannot do as much as they used to. Work loss among people with RA is highest among people whose jobs are physically demanding. Work loss is lower among those in jobs with few physical demands, or in jobs where they have influence over the job pace and activities.

Manage

RA affects many aspects of daily living including work, leisure and social activities. Fortunately, there are multiple low-cost strategies in the community that are proven to increase quality of life.

Get physically active. Experts recommend that ideally adults be moderately physically active for 150 minutes per week, like walking, swimming, or biking 30 minutes a day for five days a week. You can break these 30 minutes into three separate ten-minute sessions during the day. Regular physical activity can also reduce the risk of developing other chronic diseases such as heart disease, diabetes, and depression. Learn more about physical activity for arthritis.

Go to effective physical activity programs. If you are worried about making arthritis worse or unsure how to safely exercise, participation in physical activity programs can help reduce pain and disability related to RA and improve mood and the ability to move. Classes take place at local Ys, parks, and community centers. These classes can help people with RA feel better. Learn more about the proven physical activity programs that CDC recommends.

Join a self-management education class. Participants with arthritis and (including RA) gain confidence in learning how to control their symptoms, how to live well with arthritis, and how arthritis affects their lives. Learn more about the proven self-management education programs that CDC recommends.

Stop Smoking. Cigarette smoking makes the disease worse and can cause other medical problems. Smoking can also make it more difficult to stay physically active, which is an important part of managing RA. Get help to stop smoking by visiting I’m Ready to Quit on CDC’s Tips From Former Smokers website.

Maintain a Healthy Weight. Obesity can cause numerous problems for people with RA and so it’s important to maintain a healthy weight. 

Type 2 Diabetes

Type 2 Diabetes

Introduction 

Type 2 diabetes is a condition that happens because of a problem in the way the body regulates and uses sugar as a fuel. That sugar also is called glucose. This long-term condition results in too much sugar circulating in the blood. Eventually, high blood sugar levels can lead to disorders of the circulatory, nervous and immune systems.

In type 2 diabetes, there are primarily two problems. The pancreas does not produce enough insulin — a hormone that regulates the movement of sugar into the cells. And cells respond poorly to insulin and take in less sugar.

Type 2 diabetes used to be known as adult-onset diabetes, but both type 1 and type 2 diabetes can begin during childhood and adulthood. Type 2 is more common in older adults. But the increase in the number of children with obesity has led to more cases of type 2 diabetes in younger people.

There's no cure for type 2 diabetes. Losing weight, eating well and exercising can help manage the disease. If diet and exercise aren't enough to control blood sugar, diabetes medications or insulin therapy may be recommended.

Symptoms

Symptoms of type 2 diabetes often develop slowly. In fact, you can be living with type 2 diabetes for years and not know it. When symptoms are present, they may include:

Increased thirst.

Frequent urination.

Increased hunger.

Unintended weight loss.

Fatigue.

Blurred vision.

Slow-healing sores.

Frequent infections.

Numbness or tingling in the hands or feet.

Areas of darkened skin, usually in the armpits and neck.

Causes

Type 2 diabetes is mainly the result of two problems:

1.Cells in muscle, fat and the liver become resistant to insulin As a result, the cells don't take in enough sugar.

2.The pancreas can't make enough insulin to keep blood sugar levels within a healthy range.

Exactly why this happens is not known. Being overweight and inactive are key contributing factors.

How insulin works

Insulin is a hormone that comes from the pancreas — a gland located behind and below the stomach. Insulin controls how the body uses sugar in the following ways:

Sugar in the bloodstream triggers the pancreas to release insulin.

Insulin circulates in the bloodstream, enabling sugar to enter the cells.

The amount of sugar in the bloodstream drops.

In response to this drop, the pancreas releases less insulin.

The role of glucose

Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues. The use and regulation of glucose includes the following:

Glucose comes from two major sources: food and the liver.

Glucose is absorbed into the bloodstream, where it enters cells with the help of insulin.

The liver stores and makes glucose.

When glucose levels are low, the liver breaks down stored glycogen into glucose to keep the body's glucose level within a healthy range.

In type 2 diabetes, this process doesn't work well. Instead of moving into the cells, sugar builds up in the blood. As blood sugar levels rise, the pancreas releases more insulin. Eventually the cells in the pancreas that make insulin become damaged and can't make enough insulin to meet the body's needs.

Risk factors

Factors that may increase the risk of type 2 diabetes include:

Weight. Being overweight or obese is a main risk.

Fat distribution. Storing fat mainly in the abdomen — rather than the hips and thighs — indicates a greater risk. The risk of type 2 diabetes is higher in men with a waist circumference above 40 inches (101.6 centimeters) and in women with a waist measurement above 35 inches (88.9 centimeters).

Inactivity. The less active a person is, the greater the risk. Physical activity helps control weight, uses up glucose as energy and makes cells more sensitive to insulin.

Family history. An individual's risk of type 2 diabetes increases if a parent or sibling has type 2 diabetes.

Race and ethnicity. Although it's unclear why, people of certain races and ethnicities — including Black, Hispanic, Native American and Asian people, and Pacific Islanders — are more likely to develop type 2 diabetes than white people are.

Blood lipid levels. An increased risk is associated with low levels of high-density lipoprotein (HDL) cholesterol — the "good" cholesterol — and high levels of triglycerides.

Age. The risk of type 2 diabetes increases with age, especially after age 35.

Prediabetes. Prediabetes is a condition in which the blood sugar level is higher than normal, but not high enough to be classified as diabetes. Left untreated, prediabetes often progresses to type 2 diabetes.

Pregnancy-related risks. The risk of developing type 2 diabetes is higher in people who had gestational diabetes when they were pregnant and in those who gave birth to a baby weighing more than 9 pounds (4 kilograms).

Polycystic ovary syndrome. Having polycystic ovary syndrome — a condition characterized by irregular menstrual periods, excess hair growth and obesity — increases the risk of diabetes.

Complications

Type 2 diabetes affects many major organs, including the heart, blood vessels, nerves, eyes and kidneys. Also, factors that increase the risk of diabetes are risk factors for other serious diseases. Managing diabetes and controlling blood sugar can lower the risk for these complications and other medical conditions, including:

Heart and blood vessel disease. Diabetes is associated with an increased risk of heart disease, stroke, high blood pressure and narrowing of blood vessels, a condition called atherosclerosis.

Nerve damage in limbs. This condition is called neuropathy. High blood sugar over time can damage or destroy nerves. That may result in tingling, numbness, burning, pain or eventual loss of feeling that usually begins at the tips of the toes or fingers and gradually spreads upward.

Other nerve damage. Damage to nerves of the heart can contribute to irregular heart rhythms. Nerve damage in the digestive system can cause problems with nausea, vomiting, diarrhea or constipation. Nerve damage also may cause erectile dysfunction.

Kidney disease. Diabetes may lead to chronic kidney disease or end-stage kidney disease that can't be reversed. That may require dialysis or a kidney transplant.

Eye damage. Diabetes increases the risk of serious eye diseases, such as cataracts and glaucoma, and may damage the blood vessels of the retina, potentially leading to blindness.

Skin conditions. Diabetes may raise the risk of some skin problems, including bacterial and fungal infections.

Slow healing. Left untreated, cuts and blisters can become serious infections, which may heal poorly. Severe damage might require toe, foot or leg amputation.

Hearing impairment. Hearing problems are more common in people with diabetes.

Sleep apnea. Obstructive sleep apnea is common in people living with type 2 diabetes. Obesity may be the main contributing factor to both conditions.

Dementia. Type 2 diabetes seems to increase the risk of Alzheimer's disease and other disorders that cause dementia. Poor control of blood sugar is linked to a more rapid decline in memory and other thinking skills.

Prevention

Healthy lifestyle choices can help prevent type 2 diabetes. If you've received a diagnosis of prediabetes, lifestyle changes may slow or stop the progression to diabetes.

A healthy lifestyle includes:

Eating healthy foods. Choose foods lower in fat and calories and higher in fiber. Focus on fruits, vegetables and whole grains.

Getting active. Aim for 150 or more minutes a week of moderate to vigorous aerobic activity, such as a brisk walk, bicycling, running or swimming.

Losing weight. If you are overweight, losing a modest amount of weight and keeping it off may delay the progression from prediabetes to type 2 diabetes. If you have prediabetes, losing 7% to 10% of your body weight may reduce the risk of diabetes.

Avoiding long stretches of inactivity. Sitting still for long periods of time can increase the risk of type 2 diabetes. Try to get up every 30 minutes and move around for at least a few minutes.

For people with prediabetes, metformin (Fortamet, Glumetza, others), a diabetes medication, may be prescribed to reduce the risk of type 2 diabetes. This is usually prescribed for older adults who are obese and unable to lower blood sugar levels with lifestyle changes.

Type 1 Diabetes

Type 1 Diabetes 

Introduction

Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition. In this condition, the pancreas makes little or no insulin. Insulin is a hormone the body uses to allow sugar (glucose) to enter cells to produce energy.

Different factors, such as genetics and some viruses, may cause type 1 diabetes. Although type 1 diabetes usually appears during childhood or adolescence, it can develop in adults.

Even after a lot of research, type 1 diabetes has no cure. Treatment is directed toward managing the amount of sugar in the blood using insulin, diet and lifestyle to prevent complications.

Symptoms

Type 1 diabetes symptoms can appear suddenly and may include:

Feeling more thirsty than usual

Urinating a lot

Bed-wetting in children who have never wet the bed during the night

Feeling very hungry

Losing weight without trying

Feeling irritable or having other mood changes

Feeling tired and weak

Having blurry vision

Causes

The exact cause of type 1 diabetes is unknown. Usually, the body's own immune system — which normally fights harmful bacteria and viruses — destroys the insulin-producing (islet) cells in the pancreas. Other possible causes include:

Genetics

Exposure to viruses and other environmental factors

The Role of Insulin

Once a large number of islet cells are destroyed, the body will produce little or no insulin. Insulin is a hormone that comes from a gland behind and below the stomach (pancreas).

The pancreas puts insulin into the bloodstream.

Insulin travels through the body, allowing sugar to enter the cells.

Insulin lowers the amount of sugar in the bloodstream.

As the blood sugar level drops, the pancreas puts less insulin into the bloodstream.

The Role of Glucose

Glucose — a sugar — is a main source of energy for the cells that make up muscles and other tissues.

Glucose comes from two major sources: food and the liver.

Sugar is absorbed into the bloodstream, where it enters cells with the help of insulin.

The liver stores glucose in the form of glycogen.

When glucose levels are low, such as when you haven't eaten in a while, the liver breaks down the stored glycogen into glucose. This keeps glucose levels within a typical range.

In type 1 diabetes, there's no insulin to let glucose into the cells. Because of this, sugar builds up in the bloodstream. This can cause life-threatening complications.

Risc factors 

Some factors that can raise your risk for type 1 diabetes include:

Family history. Anyone with a parent or sibling with type 1 diabetes has a slightly higher risk of developing the condition.

Genetics. Having certain genes increases the risk of developing type 1 diabetes.

Geography. The number of people who have type 1 diabetes tends to be higher as you travel away from the equator.

Age. Type 1 diabetes can appear at any age, but it appears at two noticeable peaks. The first peak occurs in children between 4 and 7 years old. The second is in children between 10 and 14 years old.

Complications

Over time, type 1 diabetes complications can affect major organs in the body. These organs include the heart, blood vessels, nerves, eyes and kidneys. Having a normal blood sugar level can lower the risk of many complications.

Diabetes complications can lead to disabilities or even threaten your life.

Heart and blood vessel disease. Diabetes increases the risk of some problems with the heart and blood vessels. These include coronary artery disease with chest pain (angina), heart attack, stroke, narrowing of the arteries (atherosclerosis) and high blood pressure.

Nerve damage (neuropathy). Too much sugar in the blood can injure the walls of the tiny blood vessels (capillaries) that feed the nerves. This is especially true in the legs. This can cause tingling, numbness, burning or pain. This usually begins at the tips of the toes or fingers and spreads upward. Poorly controlled blood sugar could cause you to lose all sense of feeling in the affected limbs over time.

Damage to the nerves that affect the digestive system can cause problems with nausea, vomiting, diarrhea or constipation. For men, erectile dysfunction may be an issue.

Kidney damage (nephropathy). The kidneys have millions of tiny blood vessels that keep waste from entering the blood. Diabetes can damage this system. Severe damage can lead to kidney failure or end-stage kidney disease that can't be reversed. End-stage kidney disease needs to be treated with mechanical filtering of the kidneys (dialysis) or a kidney transplant.

Eye damage. Diabetes can damage the blood vessels in the retina (part of the eye that senses light) (diabetic retinopathy). This could cause blindness. Diabetes also increases the risk of other serious vision conditions, such as cataracts and glaucoma.

Foot damage. Nerve damage in the feet or poor blood flow to the feet increases the risk of some foot complications. Left untreated, cuts and blisters can become serious infections. These infections may need to be treated with toe, foot or leg removal (amputation).

Skin and mouth conditions. Diabetes may leave you more prone to infections of the skin and mouth. These include bacterial and fungal infections. Gum disease and dry mouth also are more likely.

Pregnancy complications. High blood sugar levels can be dangerous for both the parent and the baby. The risk of miscarriage, stillbirth and birth defects increases when diabetes isn't well-controlled. For the parent, diabetes increases the risk of diabetic ketoacidosis, diabetic eye problems (retinopathy), pregnancy-induced high blood pressure and preeclampsia.

Prevention

There's no known way to prevent type 1 diabetes. But researchers are working on preventing the disease or further damage of the islet cells in people who are newly diagnosed.

Ask your provider if you might be eligible for one of these clinical trials. It is important to carefully weigh the risks and benefits of any treatment available in a trial.

Autoimmune Diseases

Autoimmune Disease 

Introduction

Autoimmune diseases are conditions in which your immune system mistakenly damages healthy cells in your body. Types include rheumatoid arthritis, Crohn’s disease, and some thyroid conditions.

Your immune system usually protects you from diseases and infections. When it senses these pathogens, it creates specific cells to target foreign cells.

Usually, your immune system can tell the difference between foreign cells and your cells.

But if you have an autoimmune disease, your immune system mistakes parts of your body, such as your joints or skin, as foreign. It releases proteins called autoantibodies that attack healthy cells.

Some autoimmune diseases target only one organ. Type 1 diabetes damages your pancreas. Other conditions, such as systemic lupus erythematosus, or lupus, can affect your whole body.

Below we provide an overview of some of the most common autoimmune diseases.

Causes

Doctors don’t know exactly what causes the immune system to misfire. Yet some people are more likely to get an autoimmune disease than others.

Some factors that may increaseTrusted Source your risk of developing an autoimmune disease can include:

Your sex: People assigned female at birth between the age of 15 and 44 are more likely to get an autoimmune disease than people assigned male at birth.

Your family history: You may be more likely to develop autoimmune diseases due to inherited genes, though environmental factors may also contribute.

Environmental factors: Exposure to sunlight, mercury, chemicals like solvents or those used in agriculture, cigarette smoke, or certain bacterial and viral infections, including COVID-19Trusted Source, may increase your risk of autoimmune disease.

Ethnicity: Some autoimmune diseases are more common in people in certain groups. For example, White people from Europe and the United States may be more likely to develop autoimmune muscle disease, while lupus tends to occur more in people who are African American, Hispanic, or Latino.

Nutrition: Your diet and nutrients may impact the risk and severity of autoimmune disease.

Other health conditions: Certain health conditions, including obesity and other autoimmune diseases, may make you more likely to develop an autoimmune disease.

Common symptoms

Different autoimmune diseases may have similar early symptoms. These can include:

Fatigue

Dizziness or lightheadedness

Low grade fever

Muscle aches

Swelling

Trouble concentrating

Numbness and tingling in your hands and feet

Hair loss

Skin rash

With some autoimmune diseases, including psoriasis or rheumatoid arthritis (RA), symptoms may come and go. A period of symptoms is called a flare up. A period when the symptoms go away is called remission.

Individual autoimmune diseases can also have their own unique symptoms depending on the body systems affected. For example, with type 1 diabetes, you may experience extreme thirst and weight loss. Inflammatory bowel disease (IBD) may cause bloating and diarrhea.

Most common Autoimmune Diseases

Researchers have identified more than 100 autoimmune diseases. Here are 14 more common ones.

1. Type 1 Diabetes

Your pancreas produces the hormone insulin, which helps regulate blood sugar levels. In type 1 diabetes, the immune system destroys insulin-producing cells in your pancreas.

High blood sugar from type 1 diabetes can damage the blood vessels and organs. This can include your:

Heart

Kidneys

Eyes

Nerves

2. Rheumatoid arthritis (RA)

In RA, your immune system attacks the joints. This causes symptoms affecting the joints such as:

Swelling

Warmth

Soreness

Stiffness

While RA more commonlyTrusted Source affects people as they get older, it can also start as early as your 30s. A related condition, juvenile idiopathic arthritis, can start in childhood.

3. Psoriasis/Psoriatic arthritis

Skin cells grow and then shed when they’re no longer needed. Psoriasis causes skin cells to multiply too quickly. The extra cells build up and form inflamed patches. On lighter skin tones, patches may appear red with silver-white scales of plaque. On darker skin tones, psoriasis may appear purplish or dark brown with gray scales.

Up to 30%Trusted Source of people with psoriasis also develop psoriatic arthritis. This can cause joint symptoms that include:

Swelling

Stiffness

Pain

4. Multiple sclerosis 

Multiple sclerosis (MS) damages the protective coating surrounding nerve cells (myelin sheath) in your central nervous system. Damage to the myelin sheath slows the transmission speed of messages between your brain and spinal cord to and from the rest of your body.

This damage can lead to:

Numbness

Weakness

Balance issues

Trouble walking

Different forms of MS progress at different rates. Difficulties with walking are one of the most common mobility issues with MS.

5. Systemic lupus erythematosus (SLE)

Although doctors in the 1800s first described lupus as a skin disease because of the rash it commonly produces, the systemic form, which is most common, actually affects many organs. This can include your:

Joints

Kidneys

Brain

Heart

Common symptoms can include:

Joint pain

Fatigue

Rashes

6. Inflammatory bowel disease

IBD describes conditions that cause inflammation in the lining of the intestinal wall. Each type of IBD affects a different part of your gastrointestinal (GI) tract.

Crohn’s disease can inflame any part of your GI tract, from the mouth to the anus.

Ulcerative colitis affects the lining of the large intestine (colon) and rectum.

Common symptoms of IBD can include:

Diarrhea

Abdominal pain

Bleeding ulcers

7. Addison’s disease

Addison’s disease affects the adrenal glands, which produce the hormones cortisol and aldosterone as well as androgen hormones. Too little cortisol can affect how your body uses and stores carbohydrates and sugar (glucose). Too little aldosterone can lead to sodium loss and excess potassium in your bloodstream.

Common symptoms of Addison’s disease can include:

Weakness

Fatigue

Weight loss

Low blood sugar

8. Graves’ disease

Graves’ disease attacks the thyroid gland in your neck, causing it to produce too much of its hormones. Thyroid hormones control the body’s energy usage, known as metabolism.

Having too much of these hormones revs up your body’s activities, causing symptoms that may include:

Rapid heart rate (tachycardia)

Heat intolerance

Unintentional weight loss

Swelling of the thyroid gland (goiter)

Some people with Graves’ disease may also experience symptoms affecting the skin (Graves’ dermopathy) or eyes (Graves’ ophthalmopathy).

9. Hashimoto’s thyroiditis

In Hashimoto’s thyroiditis, thyroid hormone production slows to a deficiency. Common symptoms of Hashimoto’s thyroiditis can include:

Weight gain

Sensitivity to cold

Fatigue

Hair loss

Swelling of the thyroid (goiter)

10. Pernicious anemia

Pernicious anemia may happen when an autoimmune disorder causes your body to not produce enough of a substance called intrinsic factor. Having a deficiency in this substance reduces the amount of vitamin B12 your small intestine absorbs from food. It can cause a low red blood cell count.

Without enough of this vitamin, you’ll develop anemia, and your body’s ability for proper DNA synthesis will be altered.

It can cause symptoms that include:

Fatigue

Weakness

Headaches

This rare autoimmune disease typically occurs in people ages 60 to 70 Trusted Source and older.