Listing rare conditions
Displaying 1 - 50 of 168 in total
- Abscess of the lung
- A pocket of pus in the lung. Bacteria often reaches the lung through aspiration, in which food or secretions go down the windpipe instead of the esophagus. Other causes include spread through the blood from heart infections, certain pneumonias, certain cancers, and certain vascular disorders
- Acariasis
- An infestation of the body by one of a variety of types of mites. The most common feature is a rash.
- Acute fatty liver of pregnancy (AFLP)
- A rare, but life-threatening, complication of late pregnancy or the time immediately after delivery. It is related to a specific genetic mutation, causing fat to accumulate in the liver, potentially leading to organ failure.
- Adrenal adenoma
- A noncancerous tumor of the adrenal gland, a structure that lies above the kidneys and is important in the production of many different vital hormones. Some adenomas cause no symptoms, are diagnosed incidentally, and are not dangerous. Others may begin to release too much of a hormone, and need to be removed.
- Air embolism
- A gas bubble that has traveled through the circulatory system and become lodged inside of an artery or vein, interrupting blood flow to part of the body. Air usually enters the blood stream following certain medical and surgical procedures, but typically causes no symptoms. In rare cases, it can cause permanent damage to the organs and tissues.
- Allergy to animals
- An allergy is an abnormal reaction by the immune system to a normal substance, leading to a predictable pattern of symptoms. In the case of an allergy to animals, it is often caused by tiny particles in the air from the animal's dead skin, urine, or saliva. Symptoms range from mild to potentially life threatening.
- Amyloidosis
- One of a variety of conditions caused by accumulation of certain proteins, known as amyloids, in the organs or other tissues. Normally these proteins are in solution in blood, but may become deposited in tissues, either due to excess production or genetic disease leading to abnormal folding of the protein. This can lead to organ damage.
- Anemia of chronic disease
- Low levels in the blood of red blood cells, the cells that carry oxygen to the tissues, due to longstanding inflammatory conditions such as auto-immune disease, HIV, cancer, kidney disease, liver disease, and many others.
- Ascending cholangitis
- An infection of the bile duct, the tube that carries bile (a substance secreted by the liver that is required for digestion) from the liver to a series of tubes eventually leading to the intestine. It occurs from bacteria in the intestine traveling upwards through these tubes, often after there is already a blockage of the duct. It is a life-threatening medical emergency.
- Aspergillosis
- An infection by the fungus Aspergillus, which is commonly found in most enviroments. Infection typically occurs in those with other diseases, such as tuberculosis infection or chronic obstructive pulmonary disease, but who otherwise have healthy immune systems. People with weakened immune systems, such as patients with organs transplants or HIV/AIDS, may get a more serious version of the disease affecting multiple organs.
- Atonic bladder
- A condition in which the muscle in the wall of the bladder (the structure that holds urine) does not contact, either due to degeneration of the muscle or lack of nervous control. This leads to urinary retention, the inability to empty the bladder and release urine.
- Behcet disease
- A rare disease leading to ulcers in a variety of locations and vision problems. The exact cause is unknown, though it involves immune attack of blood vessels.
- Birth trauma
- Any damage to the tissues of a newly born child due to forces applied on it during the birthing process. Potential areas of injury include the brain and the nerves of the shoulder. Causes include the baby being in the wrong position during birth or a small pelvis in the mother. This is rare in developed countries due to c-section surgeries.
- Blastomycosis
- An infection from inhaling Blastomyces dermatitidis particles, a fungus that is found in soil. Common in the central and southeastern United States. It most often presents as a slowly progressing pneumonia.
- Blepharospasm
- An abnormal twitch of the eyelid, leading to increased blinking and involuntary closure of the eyelid. It may be secondary to pain or certain diseases, or may occur without any known cause. In the latter case, it is typically worsened by fatigue, stress, or irritants, and tends to go away on its own. Sometimes it becomes longstanding and may require treatment if bothersome.
- Carbon monoxide poisoning
- Damage to the body from inhaling toxic levels of the gas carbon monoxide. Carbon monoxide binds to the same molecule that carries oxygen, taking its place and preventing oxygen from reaching the tissues. Common sources include faulty furnaces, heaters, or stoves; leaving a running car in the garage; and fires.
- Carcinoid syndrome
- A group of symptoms occurring due to carcinoid tumors in certain parts of the bowel. Carcinoid tumors arise from neuroendocrine cells in the gut and release a variety of chemicals leading to symptoms such as flushing, diarrhea, and even heart failure.
- Cat scratch disease
- A disease caused by infection from bacteria of the Bartonella group. It is most common in children following a cat scratch or bite. In healthy people, the infection will normally clear without any medication.
- Cerebral edema
- Swelling of the brain due to too much fluid accumulating. Potential causes include physical head injury, stroke, cancer, or brain infection. If severe, it can compress the brain, which can be life threatening.
- Chagas disease
- A disease caused by infection by the parasite Trypanosoma cruzi. It is common in tropical areas of Mexico and Central and South America. It is spread by certain insects and can lead to enlargement of the heart, esophagus, or colon.
- Chancroid
- A sexually transmitted infection by the bacterial Haemophilus ducreyi. It is common in developing countries, but rare in the United States. Effective, single dose treatments exist, but if untreated it can lead to serious consequences.
- Cholesteatoma
- A noncancerous, though destructive, growth of thick skin tissue in the middle ear or the bones directy behind the ear. Some people are born with this, while others acquire it later in life (for a variety of unclear reasons). It is typically removed with surgery to prevent hearing loss.
- Chorioretinitis
- Inflammation of two thin layers of the back of the eye: the choroid (layer with many blood vessels providing nourishment) and the retina (light-sensitive layer where visual image is formed). It is most commonly caused by infections, such as toxoplasmosis, cytomegalavirus, syphyllis, and tuberculosis.
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- A nuerologic condition in which the protective coating of nerves becomes damaged, leading to weakness and loss of sensation in the arms and legs. It is thought to involve the immune system and is considered a chronic counterpart to Guillain-Barré syndrome.
- Congenital rubella
- An infection by the rubella virus occurring due to spread from a pregnant mother to the developing fetus. It can lead to deafness, eye abnormalities, heart abnormalities, and other complications. It can be prevented with vaccination.
- Connective tissue disorder
- Any of a number of diseases involving the connective tissue, the structures that support and bind together organs. These are often caused by attack by the body's immune system and involve blood vessels (termed: vasculitides).
- Conversion disorder
- A psychological condition in which psychological stress shows up in physical ways. Common symptoms include numbness, blindness, paralysis, and fits, without any identifiable physical cause. A person with conversion disorder truly believes and experiences these symptoms.
- Cryptococcosis
- A fungal infection by the fungi of the cryptococcus group. They are often found in the soil and can lead to infections of the skin, lungs, or tissues covering the brain. Infection is far more likely to occur in people with lowered immune systems, such as those with HIV/AIDS, severe liver disease, certain cancers, and those receiving immune-suppressing medications.
- Cushing syndrome
- A disorder in which there are high blood levels of the hormone cortisol, a steroid hormone involved in the body's response to stresses. It can occur for a variety of reasons, including taking too much corticosteroid medications (e.g. prednisone) or overactivity of glands involved in cortisone production and release (often as a result of a tumor).
- Cysticercosis
- Infection after exposure to eggs of Taenia solium, a tapeworm commonly found in pork. The disease is spread through contaminated food and water, potentially causing damage to the brain and muscles.
- Cyst of the eyelid
- A non-cancerous, round, thin-walled, fluid-filled pocket in the eyelid. A common example is a chalazion, which is formed when the glands that form oil to help lubricate the eye get clogged, leading to swelling and cyst formation. Though not dangerous on their own, they may become infected.
- Cytomegalovirus infection
- A common virus that at some point affects most people. Most of the time there are no symptoms and the virus is cleared, but in those that are pregnant or have a weakened immune systems, it can be dangerous. It is particularly dangerous in pregnant women, because it can spread to the fetus.
- Dengue fever
- An infectious disease caused by the dengue virus; this is most common in tropical climates. In a small percentage of people it is life threatening, involving bleeding and dangerously low blood pressure. It is transmitted by certain mosquitoes. There is no treatment or vaccine.
- Diabetes insipidus
- A condition, unrelated diabetes mellitus (the disease normally referred to as "diabetes"), in which the kidneys are not able to conserve water. This leads to increased thirst and urination. This is due to a problem with the kidneys or a problem with a hormone released by part of the brain.
- Dislocation of the ankle
- An injury to the ankle in which the bones of the foot slip out of their normal position with the bones of the lower leg, leading to pain and swelling. It often occurs after direct injury, such as car accidents or falls. It may be treated conservatively or require surgery.
- Dislocation of the foot
- An injury to the foot in which one or more of the 26 foot bones lose their normal connections with the other bones. It is often classified as either a forefoot, hind foot, or mid foot injury. It often occurs after direct injury, such as car accidents or falls. It may be treated conservatively or require surgery.
- Dislocation of the vertebra
- An injury to the spine in which the bones of the spine slip out of their normal position. It often occurs after significant direct injury, such as car accidents or falls. For this to occur, the ligaments of the spine are typically also significantly injured. This is dangerous, potentially leading to damage to the spinal cord. It may be treated conservatively or require surgery.
- Dislocation of the wrist
- An injury to the wrist in which the bones of the hand slip out of their normal position with the bones of the forearm, leading to pain and swelling. It often occurs after direct injury, such as car accidents or falls. It may be treated conservatively or require surgery.
- Dumping syndrome
- A gritty sensation which can be irritating and lead to feeling fatigued. Either tears are not produced fast enough or they evaporate too quickly. Prolonged dryness of the surface of the eye can lead to inflammation.
- Ectropion
- A condition in which the lower eyelid turns outwards. It can occur with certain congenital disorders, aging due to weakening of the lower eyelid tissues, certain anti-cancer therapies, and other causes.
- Edward syndrome
- A genetic disorder, present from birth, characterized by heart defects, physical deformities, intellectual disability, and many other problems. It is caused by an extra copy of chromosome 18. It is associated with advanced maternal age at time of pregnancy. Only 3% of cases result in live birth, and those rarely survive beyond the first year of life.
- Emphysema
- A condition in which the air sacs of the lungs are gradually destroyed, leading to increasing shortness of breath and inability to provide oxygen to the body. It can be caused by smoking, exposure to air pollutants, or a rare genetic disorder.
- Empyema
- A collection of pus in the space between the lungs and the chest wall, usually caused by spread of an infection of the lung. This can put pressure on the lungs and may require drainage to treat.
- Endometrial hyperplasia
- A condition of excess growth of the cells of the endometrium, the inner lining of the uterus (i.e. the womb). Most cases are due to high levels of estrogen hormones. This is common in obesity, polycystic ovary syndrome, certain tumors, and estrogen replacement therapy.
- Endophthalmitis
- Inflammation of the inner parts of the eyeball, typically due to infection. This is often a complication of eye surgery and can lead to blindness or loss of the entire eyeball.
- Ependymoma
- A tumor that arises from the ependyma, a tissue of the central nervous system in the brain or spinal cord.
- Epidural hemorrhage
- An accumulation of blood between the skull and the outermost layer of the meninges, the thin membranes surrounding the brain and spinal cord. It is most commonly due to direct blows to the brain, leading to damage to the blood vessels. It is a medical emergency.
- Erythema multiforme
- A rash of the skin and mucus membranes that usually follows an infection or drug exposure, possibly mediated by deposition of immune-related proteins into the area.
- Esophageal varices
- Abnormal, enlarged veins in the lower part of the esophagus, the tube that carries food from the mouth to the stomach. These most commonly occur when blood flow to the liver is blocked, leading to backup in the esophageal veins. Causes include severe liver disease, blood clots, and certain parasitic infections. This is very dangerous, due to risk of life threatening bleeding.
- Factitious disorder
- A psychological condition in which a person deliberately pretends to have an illness by exaggerating symptoms. A person may go so far as to cause themselves physical harm in order to convince others of their illness. Motives vary, but the primary aim is often to obtain sympathy and attention from taking on a "sick role."