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.

Back pain is one of the most common health problems today. In fact, most people experience back pain at some point in their lives. Normal aging and some physically demanding occupations often cause discs to wear out. Bad posture and poor...

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 treatment

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).

Pyelonephritis is an infection of the kidney. It usually starts as a urinary tract infection that spreads from the urinary tract to the bladder to the kidney. This video takes a closer look at this serious illness, which can lead to ...

Kidney stones are a common problem, affecting about 12% of men and 5% of women. Stones are typically caused by an imbalance in the urinary system: too little water, too much oxalate, or too much calcium. In this video, you'll find out ...

A kidney stone is a hard, pebble-like deposit that forms in the kidney. 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 yellow or...

Osteoarthritis is the most common form of arthritis that affects the knee. In this condition, the slippery cartilage that covers the ends of bones in knee joint wears down. This video also explores a treatment option called a fixed knee ...

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.

The anterior cruciate ligament (ACL) is one of the most common ligaments to be injured. Learn about the four major ligaments of the knee.

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. ...

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.