Aspiring Medical Students

Not having enough blood platelets. Platelets are blood cells made in the bone marrow that help clot the blood. Patients with this disorder experience bleeding into the skin and bleeding from almost any organ. The disorder can be life threatening. There are many types and causes of thrombocytopenia, such as; immune thrombocytopenic purpura, thrombotic thrombocytopenic purpura. It can also be drug induced from chemotherapy or heparin therapy, alcohol abuse, myelodysplastic syndrome and other bone marrow diseases, and infections.

Bruising, nosebleeds, bleeding gums, pinpoint red spots on the skin (petechiae), red-blue patches on the skin (purpura), bleeding from the urine or stools, black stools (melena), cuts that have prolonged bleeding

Therapy depends on the cause of the condition, the severity of the deficiency, and if there is any associated on-going bleeding. Treatment may include: platelet transfussions, intravenous immunoglobuin, plasmapheresis, plasma exchange, corticosteroids, and/or surgical remove of the spleen

Jul 22

A psychiatric disease characterized by a distorted interpretation of reality resulting in hallucinations, delusions, and disordered thinking and behaviour. Contrary to belief it does not mean a split personality. Untreated, the disease can cause severe emotional, behavioural, health and legal and financial problems. Lifelong treatment is needed, and can enable many patients to live normal productive lives. This is a serious mental disorder with abut 10% of patients committing suicide. The disease usually first appears in the teenage years.

Typically begin gradually and worsen with time and include: trouble sleeping, trouble concentrating,withdrawing from family and friends, bizarre motor behaviour in which there is less reaction to the environment (catatonic behaviour) false beliefs or thoughts (delusions), hearing voices, seeing things (hallucinations), thoughts race between unrelated topics (disordered thinking).

Depends on the severity of symptoms. but may include: anti psychotic medications. psychiatric and psychologic counselling, and/or hospitalizations

Jul 21
Schizophrenia (psychiatric disease)
Jul 21

A disease characterized by tiny clumps of inflammatory cells in different areas of the body. These clumps of inflammation are called ranulomas. The sarcoid granulomas can affect any part of the body with the most common being then lungs, lymph nodes, eyes and skin. The cause of the disorder is not known. There are increased chances of acquiring the disease for women, black Americans, and if an individual has a family history of sarcoidosis. 

Many patients do not have any symptoms and the disease is usually discovered after they obtain a chest v-ray for an unrelated reason. Any symptoms depend on the extent of the disease and the area affected. Symptoms may include; persistent cough, shortness of breath, a vague feeling of discomfort and fatigue, fever, weight loss, small red bumps on the skin, red watery eyes, swollen joints.

Many patients do not need treatment. If the disease begins to progress the healthcare provider may recommend medications including: steroids, immunosuppressive medications, anti-malarial medications and/or anti tumor necrosis factor. Lung or liver transplant may be needed for severe disease.

Jul 20

A disorder caused by a low level of vitamin D, calcium and/or phosphate in the body. These minerals and vitamins are necessary for normal bone growth and development. Deficiency of these elements causes weakening, deformity and fractures of the bones. The most common cause of these low levels is malnutrition and a poor diet. Metabolic problems causing decreased absorption or utilization of calcium, vitamin D and/or phosphorous may also cause the disorder.

Bone tenderness in arms, legs, pelvis and spine. Dental deformities, delay in teeth formation, and increased cavities. Delayed growth, short stature, increased bone fractures, bone deformities, and muscle cramps.

Therapy is aimed at reversing the cause of the vitamin and mineral deficiencies and relieving the symptoms. Replacing the calcium, phosphorous, and vitamin D can reverse the process and treat many of the symptoms. Increasing exposure to sunshine and eating more fish, liver, and milk can replace the missing vitamin D and calcium.

Note: all these notes contain relevant information specific to the AQA AS Biology Syllabus.

Disease suggests a malfunction of the body or mind which has an adverse effect on good health; it is a description of symptoms and can be mental, physical or both.

Disease is caused by Pathogens. Pathogens are disease causing microorganisms, however some microorganisms can be beneficial to us. Microorganisms include bacteria and viruses, they are too small to be seen under a microscope and are single-celled.

Transmission-when a pathogen is transferred from one individual to another, this includes bacteria, viruses and fungi.

For a microorganisms to be considered a pathogen it must;
Gain entry to the host
Colonise the tissues of the host
Resist the defences of the host
Cause damage to the host tissues.

Disease occurs when an infection leads to recognisable symptoms in the host.
An infection results from pathogens getting into the host and colonising its tissue.

Pathogens normally gain entry to the body by penetrating one of the organism’s interfaces.
An interface is a surface or boundary linking two systems (external environment with internal environment of the body. The skin forms a thick continuous layer so is an effective barrier to infection, however cuts and bites etc. can cause breaks in the skin for pathogens to gain entry.

Some interfaces have evolved to allow exchange of material between internal and external environments. This includes the digestive system (liable to diseases such as cholera and typhoid) and the gas exchange system (liable to diseases such as TB, bronchitis, influenza). However these have defences. There is a thick sticky layer of mucus that creates a barrier that covers the exchange surfaces and is difficult to penetrate. The production of enzymes breaks down pathogens. Stomach acid also kills microorganisms.

How pathogens cause disease
Disease is related to the rapidness of division which consequently effects the onset of symptoms.
Damaging host tissues – breaks down membranes of the host cells, viruses inhibit the synthesis of DNA/proteins of host cells.
Producing toxins- cholera produces a toxin that leads to excessive water loss from the intestines. Most bacterial pathogens do this.

Lifestyle choices, pathogens and genetics effect disease.
Risk; a measure of the probability that damage to health will occur as a result of a given hazard. It is measured from 0% to 100% risk, 100% risk being that harm will occur and this is usually on a time scale. However statistics can be misleading and are difficult to understand due to other factors, lifestyle or environmental.

Lifestyle choices can maximise the risk of cancer.
Smoking- this can also be passive smoking
Physical activity
Lifestyle choices can maximise the risk of CHD
High blood pressure
Blood cholesterol
Physical exercise

…to reduce both these risks…
Do not smoke
Avoid becoming overweight
Reduce salt in diet
Reduce intake of cholesterol/saturated fats
Aerobic exercise
Drinking alcohol only in moderation
Increasing dietary fibre and antioxidations 

Apr 17


It occurs most commonly in the teens and twenties, and also among the elderly. It can be caused by exposure to chemicals, drugs, radiation, infection, immune disease, and heredity; in about half the cases, the cause is unknown. The definitive diagnosis is by bone marrow biopsy; normal bone marrow has 30-70% blood stem cells, but in aplastic anemia, these cells are mostly gone and replaced by fat. Bone marrow fails to produce red blood cells, white blood cells and platelets. Although the process is usually slow, there are instances where it may occur in a very short period of time. The inadequate number of white blood cells means the body is prone to infection. Inadequate red blood cells limit the transportation of oxygen to cells and insufficient numbers of platelets may produce uncontrollable bleeding.

Fatigue, shortness of breath during exercise, rapid heart rate (due to not getting enough oxygen to respiring muscles) easy bruising, nose bleeds, bleeding gums, prolonged bleeding, frequent or severe infections.

Mild cases of aplastic anemia are treated with observation and supportive care. Blood transfusions and platelet transfusions help correct the abnormal blood counts and relieve some symptoms. Severe asplastic anemia is a life-threatening condition, and bone marrow transplant may be indicated.

Apr 8
Aplastic Anemia (Failed bone marrow)
Mar 29

Eryhthema Multiforme Major

Also referred to as Steven Johnson Syndrome, it is a life-threatening allergic reaction involving the extension of a rash with skin breakdown. The epidermis is essentially separated from the dermis due to cell death. SJS involves very serious inflammation of the skin and mucous membranes and requires aggressive treatment and hospitalization. The skin becomes red, and blisters and sloughs after dying. This disorder is usually an allergic reaction to medications or infections. The most common medications involved are sulfa drugs, tetracycline, amoxicillin, ampicillin, anti-seizure medications, nonsteroidal anti-inflammatory drugs -NSAIDs like ibuprofen, naproxen and allopurinol
SJS usually begins with fever, sore throat and fatigue, which is misdiagnosed and usually treated with antibiotics. Multiple skin blisters, sore skin spots and ulcerations in the mouth, swelling and redness of the eyes, blisters or skin rash in the area of the vagina or genitals, itching, fever, general ill feeling, and joint aches.
Intensive burn care treatment, hospitalization and intravenous fluids. Patients can become dangerously dehydrated and acquire infections of their skin lesions.


Mar 25

Bell’s Palsy
Bell’s palsy is a condition that causes temporary weakness or paralysis of the muscles in one side of the face. It is the most common cause of facial paralysis. Bell’s palsy is a rare condition that affects about 1 in 5,000 people a year. It more commonly affects those aged between 15 and 45 but people outside this age group can also suffer from the condition. Both men and women are affected equally. Bell’s palsy is more common in pregnant women and those with diabetes and HIV, for reasons that are not yet fully understood.

The symptoms of Bell’s palsy vary from person to person. The weakness on one side of the face can be described as either:  partial palsy, which is mild muscle weakness or complete palsy, which is no movement at all (paralysis) – although this is very rare. Bell’s palsy can also affect the eyelid and mouth, making it difficult to close and open them and in rare cases, it can affect both sides of a person’s face. Bell’s palsy is only diagnosed if other possible causes of these symptoms are ruled out, such as stroke or a tumour. Around 3 in 10 people with Bell’s palsy will continue to experience weakness in their facial muscles, and 2 in 10 will be left with a more serious long-term problem. Complications can include speech problems, reduced sense of taste and the permanent tensing of the facial muscles.

Bell’s palsy is believed to occur when the nerve that controls the muscles in your face becomes compressed. The exact cause is unknown, although it’s thought to be because the facial nerve becomes inflamed, possibly due to a viral infection. Variants of the herpes virus may be responsible.


Around 7 out of 10 people with Bell’s palsy make a complete recovery, with or without treatment. Most people notice an improvement in their symptoms after about two to three weeks. However, a complete recovery can take between three and and six months. The  recovery time varies from person to person and will depend on the amount of nerve damage. Steroids, usually prednisolone, are used to reduce the swelling of the facial nerve. Eye drops may be required to prevent problems if you are unable to close your eye. Tape may also be used to close the eye whilst sleeping. 

Mar 24


Elephantiasis is characterized by the gross enlargement of a limb or areas of the trunk or head and is found most commonly in African nations. There is an abnormal accumulation of watery fluid in the tissues (edema) causing severe swelling. The skin usually develops a thickened, pebbly appearance and may become ulcerated and darkened. Fever, chills and a general feeling of ill health (malaise) may be present.

Elephantiasis may also affect the male and female genital organs. In a male, there may be enlargement of the scrotum, and the penis may be retracted under skin which has become thickened, nonelastic, hot and painful. The spermatic cords may become thickened.

The external parts of the female genital organs (vulva) may also be affected by elephantiasis. A long, tumorous mass covered by thickened and ulcerated skin may develop between the thighs. There may also be an enlargement of the lymph nodes of the legs.

The extreme enlargement of the limbs and other areas of the body characterized by elephantiasis, is the result of obstruction of the lymph flow and possibly of blood circulation. The lymphatic blockage can be due to recurrent attacks of a bacterial infection which causes inflammation of the lymphatic vessels (streptococcal lymphangitis). When the lymphatic obstruction is large enough, back pressure in the lymphatic channels produces dilation of the superficial vessels, resulting in extreme swelling. Without medical intervention, the cycle continues until the affected area is grotesquely enlarged. Death of surrounding tissues may also occur from an obstructed blood supply (gangrene).

Recent studies have shown that a possible cause of elephantiasis in Africa may be related to the red soil on which certain barefooted populations live. It is believed that small chemical particles found in the soil may enter the skin through the bare feet. These particles then lodge in the lymphatic tissuesand produce irritating effects. The traumatized tissue is then vulnerable to streptococcal infection.

Standard Therapies

Treatment can include chemotherapy to attack the adult worms as well as symptomatic treatment to repair damage caused by the body’s reaction to the presence of dead worms. Drugs including Suramin (Antrypol ), Diethylcarbamazine (DEC, Heterazan, Banocide, and Notezine ), Ivermectin (Mectizan), Metrifonate (Trichlorphon), Mebendazole and Levamisole have shown to be effective in treating conditions associated with a filarial infection.

Failure of the Lymphatic system due to an infection provides an opportunity for microbial infections to develop. These infections can be minimized by proper anisepticalyl hygenic care. Surgery can be performed to remove or bypass damaged lymphatic regions.

Investigational Therapies

It has recently come to my attention via a massage therapy student that lymphatic massage has been successful in treating some cases.

This disease entry is based upon medical information available through July 1990. Since NORD’s resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.





Mar 18

Anencephaly is a birth defect, it is not varied on race or having a history of genetic problems.This occurs when the head end of the neural tube fails to close. Babies born with this disorder are without a scalp or cerebellum, meninx, both hemispheres of the brain and the vault of the cranium/skull. They usually have at least part of the brain stem and any remaining brain tissue is protected by a thin membrane. Anencephaly occurs in 1 in 1000 babies. More baby girls develop it than baby boys, with a 3:2 ratio.


Not much is known, studies have shown that a mother who gets plenty of folic acid in her diet is less likely to have a baby with anencephaly. If all women of child-bearing age took 0.4mg of folic acid every day before and at least until the end of the first term of their pregnancy, between 50 and 70% of potential cases of anencephaly could be prevented and other defects that involve the neural tube. Although it shows up in ultrasounds very well, so the diagnosis is reliable within 11-14 weeks of gestation, some opt for abortion whilst some babies are stillborn (about 25%) and the ones that survive normally live about 6 days.

There is no current therapy for anencephaly.