Boil  A boil is a painful, pus-filled bump under your skin — the result of a bacterial infection of one or more hair follicles. Carbuncle  A carbuncle is a cluster of boils — painful, pus-filled bumps ...

Facing a breast cancer diagnosis can be overwhelming. Your stress levels may skyrocket. You may worry about finances. And you may be asking yourself difficult questions, such as whether to write a living will. Education and supportive care can hel...

Facing a breast cancer diagnosis can be overwhelming. Your stress levels may skyrocket. You may worry about finances. And you may be asking yourself difficult questions, such as whether to write a living will. Education and supportive care can hel...

Chlamydia is the most commonly reported sexually transmitted disease (STD) in the U.S. It is an infection with the bacteria known as Chlamydia trachomatis. Chlamydia is very similar to gonorrhea in its symptoms and pattern of transmission. It is i...

Collagenous colitis is a rare digestive disorder that primarily affects females and typically becomes apparent during middle age. The disorder is characterized by inflammatory changes of the mucous membranes (mucosa) of the colon (colitis) and abn...

Mixed connective tissue disease facts Connective tissues are the framework of the cells of the body. Mixed connective tissue disease is an "overlap" combination of connective tissue diseases. Diagnosis of mixed c...

Cytomegalovirus (CMV) is a common virus that belongs to the herpesvirus family. It can infect people of all ages and is usually harmless to those with a healthy immune system. However, it can cause serious complications in individuals with weakene...

Dandy-Walker malformation (DWM) is a brain malformation that occurs during embryonic development of the cerebellum and 4th ventricle. The cerebellum is the area of the brain that helps coordinate movement, and is also involved with cognition and b...

Dandy-Walker malformation (DWM) is a brain malformation that occurs during embryonic development of the cerebellum and 4th ventricle. The cerebellum is the area of the brain that helps coordinate movement, and is also involved with cognition and b...

Dandy-Walker malformation (DWM) is a brain malformation that occurs during embryonic development of the cerebellum and 4th ventricle. The cerebellum is the area of the brain that helps coordinate movement, and is also involved with cognition and b...

Dandy-Walker malformation (DWM) is a brain malformation that occurs during embryonic development of the cerebellum and 4th ventricle. The cerebellum is the area of the brain that helps coordinate movement, and is also involved with cognition and b...

Dental plaque is a sticky, colorless film of bacteria that forms on the teeth and along the gumline. It is constantly forming on the teeth and can lead to tooth decay and gum disease if not removed regularly through proper oral hygiene practices s...

Dental tartar, also known as dental calculus, is a hard, yellowish or brownish deposit that forms on the teeth when plaque hardens. Plaque is a sticky film of bacteria that forms on the teeth when sugars and starches in food interact with the bact...

Diphtheria is a serious bacterial infection that usually affects the mucous membranes of the throat and nose. It is caused by the bacterium Corynebacterium diphtheriae and is spread through respiratory droplets or direct contact with an infected p...

Harlequin ichthyosis is a rare genetic skin disorder. The newborn infant is covered with plates of thick skin that crack and split apart. The thick plates can pull at and distort facial features and can restrict breathing and eating. Harlequin inf...

Elephantiasis is a condition characterized by gross enlargement of an area of the body, especially the limbs. Other areas commonly affected include the external genitals. Elephantiasis is caused by obstruction of the lymphatic system, which result...

Elephantiasis is a condition characterized by gross enlargement of an area of the body, especially the limbs. Other areas commonly affected include the external genitals. Elephantiasis is caused by obstruction of the lymphatic system, which result...

Polycythemia vera is a rare, chronic disorder involving the overproduction of blood cells in the bone marrow (myeloproliferation). The overproduction of red blood cells is most dramatic, but the production of white blood cells and platelets are al...

Eye lymphoma is a type of cancer that affects the eye. It is a rare form of non-Hodgkin lymphoma, which is a type of cancer that affects the lymphatic system. Eye lymphoma can affect the eye itself, the orbit (the area around the eye), or the eyel...

Familial eosinophilic cellulitis is a rare skin disorder. It is characterized by raised, red, swollen, and warm areas of skin, in a flame-shaped pattern with associated pain. The exact cause of the disease is unknown. However, bites of spiders, be...

Folliculitis facts Folliculitis is a very common, benign skin disorder that appears as pinpoint red bumps sometimes with a small dot of pus at the top. Folliculitis affects people of all ages, from babies to seniors. ...

Fountain syndrome is an extremely rare inherited disorder that is characterized by mental retardation; abnormal swelling of the cheeks and lips due to the excessive accumulation of body fluids under the skin (subcutaneous) of the face (edema); ske...

Genital herpes is a sexually transmitted disease caused by herpes simplex virus (HSV). HSV causes genital herpes by entering the skin or mucous membranes through microscopic breaks in the skin and mucous membranes. Genital...

Giant Papillary Conjunctivitis (GPC) is an inflammatory condition of the eye that affects the inner surface of the eyelids. It is caused by an allergic reaction to contact lenses, foreign bodies, or other irritants. Symptoms include itching, redne...

Gingivitis is a common and mild form of gum disease that causes irritation, redness, and swelling (inflammation) of the gingiva, the part of the gum around the base of the teeth. It is usually caused by poor oral hygiene that allows plaque to buil...

Forbes disease (GSD-III) is one of several glycogen storage disorders (GSD) that are inherited as autosomal recessive traits. Symptoms are caused by a lack of the enzyme amylo-1,6 glucosidase (debrancher enzyme). This enzyme deficiency causes exce...

Forbes disease (GSD-III) is one of several glycogen storage disorders (GSD) that are inherited as autosomal recessive traits. Symptoms are caused by a lack of the enzyme amylo-1,6 glucosidase (debrancher enzyme). This enzyme deficiency causes exce...

Familial eosinophilic cellulitis is a rare skin disorder. It is characterized by raised, red, swollen, and warm areas of skin, in a flame-shaped pattern with associated pain. The exact cause of the disease is unknown. However, bites of spiders, be...

Harlequin ichthyosis is a rare genetic skin disorder. The newborn infant is covered with plates of thick skin that crack and split apart. The thick plates can pull at and distort facial features and can restrict breathing and eating. Harlequin inf...

According to the American Heart Association, about 5 million Americans are diagnosed with valvular heart disease each year. What Is Valvular Heart Disease? Heart valve disease occurs when your heart's valves do not work the way the...

Herpes Simplex Virus (HSV) is a common viral infection that causes sores or blisters on the skin or mucous membranes. There are two types of HSV: HSV-1, which typically causes cold sores or fever blisters around the mouth, and HSV-2, which typical...

Herpetic gingivostomatitis is a viral infection caused by the herpes simplex virus. It is characterized by painful sores and ulcers in the mouth and on the gums, as well as fever, swollen lymph nodes, and general malaise. It is a common infection ...

Hirschsprung* disease (HD) is a disease of the large intestine that causes severe constipation or intestinal obstruction. Constipation means stool moves through the intestines slower than usual. Bowel movements occur less often than normal and sto...

Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system, specifically targeting CD4 cells (T cells), which help the body fight off infections. If left untreated, HIV can lead to the disease known as Acquired Immunodeficiency S...

Hydrocele facts While hydroceles may occur in either gender, they are much more common in males. A hydrocele is a collection of clear fluid in a thin walled sack present in the scrotum. Hydroceles may be either o...

Harlequin ichthyosis is a rare genetic skin disorder. The newborn infant is covered with plates of thick skin that crack and split apart. The thick plates can pull at and distort facial features and can restrict breathing and eating. Harlequin inf...

Harlequin ichthyosis is a rare genetic skin disorder. The newborn infant is covered with plates of thick skin that crack and split apart. The thick plates can pull at and distort facial features and can restrict breathing and eating. Harlequin inf...

Kawasaki's disease facts Kawasaki's disease is a syndrome of unknown cause that mainly strikes young children. Signs of the disease include fever and redness of the eyes, hands, feet, mouth, and tongue. The disea...

Kohler disease is a rare bone disorder of the foot in children that may be the result of stress-related compression at a critical time during the period of growth. It is characterized by limping caused by pain and swelling in the foot. It most oft...

Kohler disease is a rare bone disorder of the foot in children that may be the result of stress-related compression at a critical time during the period of growth. It is characterized by limping caused by pain and swelling in the foot. It most oft...

Kohler disease is a rare bone disorder of the foot in children that may be the result of stress-related compression at a critical time during the period of growth. It is characterized by limping caused by pain and swelling in the foot. It most oft...

Systemic lupus erythematosus (SLE) is an autoimmune disease. SLE is characterized by the production of unusual antibodies in the blood. SLE is eight times more common in women than men. The cause(s) of SLE is (ar...

Marinesco-Sjogren syndrome (MSS) is a rare genetic disorder that affects multiple organ systems of the body. Common symptoms include difficulty coordinating voluntary movements due to degeneration (atrophy) of the cerebellum (cerebellar ataxia), c...

Milk allergy is an abnormal response by the body's immune system to milk and products containing milk. It's one of the most common food allergies in children. Cow's milk is the usual cause of milk allergy, but milk from sheep, goats, buffalo and o...

Megalocornea-mental retardation (MMR) syndrome, otherwise known as Neuhauser syndrome, is an extremely rare genetic disorder characterized by distinctive abnormalities of the eye, several degrees of cognitive impairment, and a wide variety of addi...

Mononucleosis, commonly known as mono, is a viral infection caused by the Epstein-Barr virus (EBV). It is most commonly seen in teenagers and young adults, but can affect people of any age. Mono is typically spread through saliva, which is why it ...

Turner syndrome is a rare chromosomal disorder that affects females. The disorder is characterized by partial or complete loss (monosomy) of one of the X chromosomes. Turner syndrome is highly variable and can differ dramatically from one person t...

Marinesco-Sjogren syndrome (MSS) is a rare genetic disorder that affects multiple organ systems of the body. Common symptoms include difficulty coordinating voluntary movements due to degeneration (atrophy) of the cerebellum (cerebellar ataxia), c...

Mucha-Habermann disease, also known as pityriasis lichenoides et varioliformis acuta or PLEVA, is a rare skin disorder. The lesions most often appear on the trunk and the arms and legs. Lesions tend to develop in small groups. Mucha-Habermann dise...

Mumps is a contagious viral infection that primarily affects the salivary glands, causing swelling and pain in the cheeks and jaw. It is spread through respiratory droplets, such as coughing or sneezing, and can also be transmitted through close p...

Oral lichen planus is a chronic inflammatory condition that affects the mucous membranes inside the mouth. It is characterized by the presence of white, lacy patches or sores on the inside of the cheeks, gums, tongue, and other areas of the mouth....

What is pericarditis? The heart muscle has a tight covering that surrounds it, a lining sac called the pericardium (peri=around +cardium=heart). This sac actually has two layers. The visceral pericardium is only one cell layer thick and fi...

Periodontitis is a serious gum infection that damages the soft tissue and destroys the bone that supports your teeth. It is a common cause of tooth loss in adults and is typically caused by poor oral hygiene that allows bacteria in plaque to build...

Photokeratitis is a painful eye condition caused by exposure to ultraviolet (UV) radiation. It is sometimes referred to as "snow blindness" or "welder's flash." Symptoms of photokeratitis include redness, tearing, pain, and temporary vision loss. ...

Cholinergic urticaria is a relatively common disorder of the immune system characterized by an immediate skin reaction (hypersensitivity) to heat, emotional stress, and/or exercise. Symptoms of the disorder include the appearance of distinctive sm...

Cholinergic urticaria is a relatively common disorder of the immune system characterized by an immediate skin reaction (hypersensitivity) to heat, emotional stress, and/or exercise. Symptoms of the disorder include the appearance of distinctive sm...

If you're a woman, you may be more familiar with the premenstrual syndrome than you'd like to be. But do you know when a problem period indicates that a visit to your doctor is in order? For most women, menstrual cycles last between 21 and...

Psoriatic arthritis facts Psoriatic arthritis is a chronic disease characterized by a form of inflammation of the skin (psoriasis) and joints (inflammatory arthritis). Some 10%-15% of people with psoriasis also develop inf...

Psoriatic arthritis is a chronic disease characterized by a form of inflammation of the skin (psoriasis) and joints (inflammatory arthritis). Some 10%-15% of people with psoriasis also develop inflammation of joints (psoriatic arthr...

Infectious arthritis is an inflammation of one or more joints that occurs as a result of infection by bacteria, viruses or, less frequently, fungi or parasites. The symptoms of Infectious arthritis depend upon which agent has caused the infection ...

Infectious arthritis is an inflammation of one or more joints that occurs as a result of infection by bacteria, viruses or, less frequently, fungi or parasites. The symptoms of Infectious arthritis depend upon which agent has caused the infection ...

A ranula is a type of cyst that forms on the floor of the mouth, usually under the tongue. It is typically filled with mucus and can cause swelling and discomfort. Ranulas are usually harmless, but they can sometimes become infected or grow large ...

Rheumatoid arthritis is a chronic inflammatory disorder that can affect more than just your joints. In some people, the condition can damage a wide variety of body systems, including the skin, eyes, lungs, heart and blood vessels. An autoi...

Rheumatoid arthritis is a chronic inflammatory disorder that can affect more than just your joints. In some people, the condition can damage a wide variety of body systems, including the skin, eyes, lungs, heart and blood vessels. An autoi...

Rosacea (roe-ZAY-she-uh) is a common skin condition that causes redness and visible blood vessels in your face. It may also produce small, red, pus-filled bumps. These signs and symptoms may flare up for a period of weeks to months and then dimini...

Rubella, also known as German measles, is a contagious viral infection that causes a mild fever and a red rash on the skin. It is typically a mild illness, but can be more serious for pregnant women, as it can cause birth defects in the developing...

The sarcoid of boeck (sarcoidosis) is a chronic inflammatory disease that can affect any organ in the body, but most often involves the skin and lungs.  Sarcoid of boeck is characterized by the formation of small, round bumps (...

Scleritis is an inflammation of the sclera, the white outer layer of the eye. It is a rare condition that can cause severe eye pain, redness, and blurred vision. It can also lead to vision loss if left untreated. Treatment typically involves the u...

Tonsillitis is an inflammation of the tonsils, which are two small glands located at the back of the throat. It is usually caused by a viral or bacterial infection and can result in symptoms such as sore throat, difficulty swallowing, fever, and s...

Toxoplasmosis is a disease caused by the Toxoplasma gondii parasite. It is commonly found in cat feces and can also be present in contaminated soil, water, and raw or undercooked meat. In healthy individuals, toxoplasmosis may cause mild flu-like ...

Turf toe is an injury to the underside of the big toe and joint at the base of the big toe. This joint, the first metatarsalphalangeal (MTP) joint, is commonly known as the "ball of the foot." Turf toe is specifically a sprain of the big toe joint...