In Kaposi sarcoma (KS), cancer starts in the cells that form the lining of lymph or blood vessels. Learn more about symptoms, diagnosis, and treatments.

Kawasaki disease causes inflamed blood vessels. It can weaken the walls of blood vessels, including the arteries of the heart. Kawasaki mostly affects infants and young children. It is uncommon in the U.S.

Keratitis is an inflammation or infection of the cornea of the eye. The cornea is the clear, dome-shaped surface that covers the front of the eye.

Keratoconus is an eye disorder in which your cornea slowly thins over time. The cornea also bulges out over time, to form a cone-like shape. Keratoconus causes nearsightedness (myopia) and blurry vision.

Detailed information on keratosis pilaris, including symptoms, diagnosis, and treatment.

Kidneys are a pair of organs located on either side of the spine in the mid-back region. They function to remove water, excess salt and waste products in the form of urine from the body. Urine that is produced by the kidneys is ...

A helpful guide to kidney cancer, from symptoms and diagnosis to getting a second opinion and types of treatment.

Kidney disease (renal failure) is short-term or permanent damage to the kidneys that results in loss of normal kidney function.

Kidney failure happens when damage results in loss of normal kidney function. It may also be called end stage renal disease (ESRD).

A kidney stone is a hard, pebble-like deposit that forms in 1 or both kidneys. It may be as small as a grain of sand or as large as a pearl. Some are as big as golf balls. A stone may be smooth, irregular in shape, or jagged. Most are ...

Knee pain is a common complaint for which there can be many causes. It is important to make an accurate diagnosis of the cause of your symptoms so that appropriate treatment can be directed at the cause.

Learn about the 4 major ligaments of the knee, and about common injuries, symptoms, and treatment.

Knee pain is very common, especially in highly active people who put a lot of pressure on their knees, such as runners. Read on to learn more about this condition.

One of the most important orthopedic surgical advances of this century, knee replacement was first performed in 1968. Improvements in surgical materials and techniques since then have greatly increased the procedure's effectiveness. ...

Also called patellar sublimation, patients who experience an unstable kneecap have a patella that does not track evenly within its groove on the femur. Depending on the severity, this improper tracking may not cause the patient any ...

A spine affected by kyphosis has a forward curvature of the back bones (vertebrae) in the upper back area, giving an abnormally rounded or humpback appearance.

Kyphosis is a deformity of the backbone (spine). It's when the bones of the spine (vertebrae) in the upper back curve outward more than they should.