Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells. It often causes whiteheads, blackheads or pimples, and usually appears on the face, forehead, chest, upper back and shoulders. Acne is most ...

What is the bladder? The urinary bladder, or the bladder, is a hollow organ in the pelvis. Most of it lies behind the pubic bone of the pelvis, but when full of urine, it can extend up into the lower part of the abdomen. Its primary functi...

What is the bladder? The urinary bladder, or the bladder, is a hollow organ in the pelvis. Most of it lies behind the pubic bone of the pelvis, but when full of urine, it can extend up into the lower part of the abdomen. Its primary functi...

Female urinary system Your urinary system — which includes the kidneys, ureters, bladder and urethra — is responsible for removing waste from your body through urine. Your kidneys, located toward the back in your upper abdomen,...

Female urinary system Your urinary system — which includes the kidneys, ureters, bladder and urethra — is responsible for removing waste from your body through urine. Your kidneys, located toward the back in your upper abdomen,...

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 ...

Chickenpox (varicella) is a viral infection that causes an itchy rash with small, fluid-filled blisters. Chickenpox is highly contagious to people who haven't had the disease or been vaccinated against it. Before routine chickenpox vaccination, vi...

Chlamydia is a common sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. It can be transmitted through unprotected sexual contact with an infected person. Chlamydia can infect both men and women and can cause sympt...

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...

Cold sores, also known as fever blisters, are small blisters that typically appear on or around the lips. They are caused by the herpes simplex virus (HSV), specifically HSV-1. Cold sores are highly contagious and can be spread through close perso...

Ulcerative colitis (UL-sur-uh-tiv koe-LIE-tis) is an inflammatory bowel disease ...

Ulcerative colitis (UL-sur-uh-tiv koe-LIE-tis) is an inflammatory bowel disease (IBD) that causes inflammation and ulcers (sores) in your digestive tract. Ulcerative colitis affects the innermost lining of your large intestine (colon) and rectum. ...

Contact dermatitis facts Contact dermatitis is a rash that occurs at the site of exposure to a substance capable of producing an allegic or irritant skin response. Contact dermatitis can be caused by noxious, irritating su...

Autosomal dominant interstitial kidney disease describes a group of diseases affecting solely the proper function of the kidney and having the following characteristics: They are inherited in an autosomal dominant manner; kidney disease develops, ...

Diabetes and foot problems facts Two main conditions, peripheral artery disease (PAD) and peripheral neuropathy, are responsible for the increased risk of foot problems in people with diabetes. People with diabetes have an...

Though ulcers often heal on their own, you shouldn't ignore their warning signs. If not properly treated, ulcers can lead to serious health problems, including: Bleeding Perforation (a hole through the wall of the stomach)...

Dysplasia epiphysealis hemimelica, also known as Trevor disease, is a rare skeletal developmental disorder of childhood. It is characterized by an overgrowth of cartilage on the ends (epiphyses) of the long bones of the arms and legs and the bones...

Endometriosis is the abnormal growth of cells (endometrial cells) similar to those that form the inside of the uterus, but in a location outside of the uterus. Endometriosis is most commonly found on other organs of the pelvis. The ...

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...

Schindler disease is a rare inherited metabolic disorder characterized by the deficient activity of the lysosomal enzyme alpha-N-acetylgalactosaminidase (alpha-NAGA or alpha-galactosidase B). The enzyme defect leads to the abnormal accumulation of...

Genital herpes, also known as herpes simplex virus type 2 (HSV-2), is a sexually transmitted infection that causes painful sores and blisters on the genital area. It is a chronic condition that can flare up periodically, causing symptoms such as i...

Gonorrhea is a sexually transmitted infection (STI) caused by the bacterium Neisseria gonorrhoeae. It can infect both men and women and is most commonly spread through unprotected sexual contact. Symptoms of gonorrhea can include painful urination...

Acquired agranulocytosis is a rare, drug-induced blood disorder that is characterized by a severe reduction in the number of white blood cells (granulocytes) in the circulating blood. The name granulocyte refers to grain-like bodies within the cel...

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 ...

Intertrigo is a dermatitis that only affects skin folds. Intertrigo is caused when skin is irritated by friction, which is enhanced by moisture and heat. Risk factors for intertrigo include obesity, heat, and humidity....

Until recently the relationship of Stevens-Johnson syndrome to other severe blistering disorders was a matter of some debate. Now a consensus seems to be evolving that describes SJS as a rare disorder involving lesions of the mucous membranes alon...

Dercum's disease is an extremely rare disorder characterized by multiple, painful growths consisting of fatty tissue (lipomas). These growths mainly occur on the trunk, the upper arms and upper legs and are found just below the skin (subcutaneousl...

Granuloma annulare is a chronic degenerative skin disorder. The most common form is localized granuloma annulare, which is characterized by the presence of small, firm red or yellow colored bumps (nodules or papules) that appear arranged in a ring...

Lichen Planus is a rare, recurrent, itchy rash or area of inflammatory eruptions (lesions) of unknown origin characterized by shiny reddish-purple spots on the skin and gray-white ones in the mouth. The disorder may present as itchy spots on the w...

Mesothelioma is a rare form of cancer that affects the membrane that covers and protects various internal organs of the body (mesothelium). The mesothelium is composed of two layers of specialized cells known as mesothelial cells. One layer direct...

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...

Flesh-eating bacteria (necrotizing fasciitis) is a rare infection of the skin and tissues below it. It can be deadly if not treated quickly. Necrotizing fasciitis spreads quickly and aggressively in an infected person. It causes tissue dea...

Neuropathic pain is a pain condition that’s usually chronic. It’s usually caused by chronic, progressive nerve disease, and it can also occur as the result of injury or infection. If you have chronic neuropathic pain, it can fl...

Tolosa-Hunt syndrome is a rare disorder characterized by severe periorbital headaches, along with decreased and painful eye movements (ophthalmoplegia). Symptoms usually affect only one eye (unilateral). In most cases, affected individuals experie...

Tolosa-Hunt syndrome is a rare disorder characterized by severe periorbital headaches, along with decreased and painful eye movements (ophthalmoplegia). Symptoms usually affect only one eye (unilateral). In most cases, affected individuals experie...

Neuromyelitis optica, also known as Devic disease (DD), is a chronic disorder of nerve tissue characterized by inflammation of the optic nerve (optic neuritis) and inflammation of the spinal cord (myelitis). There appear to be two forms of this di...

Neuromyelitis optica, also known as Devic disease (DD), is a chronic disorder of nerve tissue characterized by inflammation of the optic nerve (optic neuritis) and inflammation of the spinal cord (myelitis). There appear to be two forms of this di...

Ovarian cysts facts Ovarian cysts are closed, sac-like structures within the ovary that are filled with a liquid or semisolid substance. Ovarian cysts form for numerous reasons. Pain in the abdomen or pelvis is t...

Idiopathic nodular panniculitis is a rare spectrum of skin disorders characterized by single or multiple, tender or painful bumps below the surface of the skin (subcutaneous nodules) that usually lead to inflammation of the subcutaneous layer of f...

Idiopathic nodular panniculitis is a rare spectrum of skin disorders characterized by single or multiple, tender or painful bumps below the surface of the skin (subcutaneous nodules) that usually lead to inflammation of the subcutaneous layer of f...

Pelvic Inflammatory Disease (PID) is an infection of the female reproductive organs, including the uterus, fallopian tubes, and ovaries. It is usually caused by sexually transmitted infections such as chlamydia and gonorrhea, but can also be cause...

Penile cancer is a disease in which malignant (cancer) cells form in the tissues of the penis. The penis is a rod-shaped male reproductive organ that passes sperm and urine from the body. It contains two types of erectile tissue (spongy ti...

Penile cancer is a disease in which malignant (cancer) cells form in the tissues of the penis. The penis is a rod-shaped male reproductive organ that passes sperm and urine from the body. It contains two types of erectile tissue (spongy ti...

Pleuropulmonary blastoma (PPB) is a rare childhood cancer occurring in the chest, specifically in the lungs or in the coverings of the lungs called "pleura". PPB occurs almost exclusively in children under the age of approximately 7-8 years and ra...

Langerhans cell histiocytosis (LCH) is a spectrum of rare disorders characterized by overproduction (proliferation) and accumulation of a specific type of white blood cell (histiocyte) in the various tissues and organs of the body (lesions). The l...

Though they're not cancerous, sebaceous cysts can be irritating. A sebaceous cyst is a small lump or bump under the skin. This type of cyst is not cancerous. They are most often found on the face, neck, upper back, and upper chest,...

Familial idiopathic basal ganglia calcification (FIBGC) is a rare neurological disorder characterized by the presence of abnormal calcium deposits (calcifications) of unknown cause. Associated symptoms include progressive deterioration of cognitiv...

Reflex sympathetic dystrophy syndrome (RSDS), also known as complex regional pain syndrome, is a rare disorder of the sympathetic nervous system that is characterized by chronic, severe pain. The sympathetic nervous system is that part of the auto...

Sweet syndrome is a rare skin disorder characterized by fever, inflammation of the joints (arthritis), and the sudden onset of a rash. The rash consists of bluish-red, tender papules that usually occur on the arms, legs, face or neck, most often o...

What are yeast infections? What are commonly known as "yeast" infections are caused by various species of a yeast-like fungus called Candida, particularly the species Candida albicans. Yeast organisms are part of the germs (including bacte...

Dystonia is a group of movement disorders that vary in their symptoms, causes, progression, and treatments. This group of neurological conditions is generally characterized by involuntary muscle contractions that force the body into abnormal, some...

Trichomoniasis is a common sexually transmitted infection caused by a parasite. In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching and painful urination. Men who have trichomoniasis typically have no symp...

Trichomoniasis is a common sexually transmitted infection caused by a parasite. In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching and painful urination. Men who have trichomoniasis typically have no symp...

Porphyria cutanea tarda (PCT) is a type of porphyria in which affected individuals are sensitive to sunlight. Exposed skin shows abnormalities that range from slight fragility of the skin to persistent scarring and disfiguration. Due to fragility ...

Uterine fibroids facts Uterine fibroids are benign tumors that originate in the uterus (womb). It is not known exactly why women develop uterine fibroids. Most women with uterine fibroids have no symptoms. Howeve...

Normal vaginal bleeding is the periodic blood flow from the uterus. Normal vaginal bleeding is also called menorrhea. The process by which menorrhea occurs is called menstruation. In order to determine whether bleeding is ...

Vaginal atrophy is the medical term that refers to the thinning of the wall of the vagina that occurs during the menopause (the time when menstrual periods have ceased) in women. Vaginal atrophy occurs due to falling estrogen levels...

Vaginal pain and vulvodynia facts Vulvodynia refers to pain in the area of the vulva and vaginal opening for which no cause can be identified. Vulvodynia is not related to sexually-transmitted diseases (STDs). Th...