An anal stricture is a narrowing of the end of the tube (anal canal) that takes stool out of the body. This can cause pain and other problems with passing stool. Learn more about this condition, including what causes it, what the symptoms are, and how it's treated.

Alopecia areata is a condition that causes your hair to fall out. It causes bald patches on the scalp, but it can also cause hair loss on other parts of the body.

Actinic keratosis is a skin growth caused by sun damage. Many people get these growths, especially as they age. This is because of regular exposure to the sun over years.

Acanthosis nigricans is a skin condition that appears as dark, thick patches on the skin. Learn more about this condition, including causes, symptoms, and treatment.

Zika is a virus spread through the bite of a mosquito. It may also be passed on through sexual contact and blood transfusions.

Yersiniosis is a foodborne illness. It causes inflammation in the small intestine and colon. It is more common in children.

Tinea unguium is a type of fungal infection. The fungus infects the fingernails and, more commonly, the toenails. It's more common in men, older adults, and people who have diabetes or peripheral vascular disease.

Tinea cruris is a type of fungal infection. The fungus infects the skin in the groin. It is more commonly called jock itch.

Shigellosis is a digestive illness caused by bacteria. You can get it by eating or drinking contaminated food or water.

An intrathecal pain pump implant is a way to relieve some kinds of long-term pain or cancer pain. It sends pain medicine through a thin, flexible tube. The tube is inserted into the space around the spinal cord.