Between the bones of the knees are two crescent-shaped disks of connective tissue, called menisci, which also act as shock absorbers to cushion the lower part of the leg from the weight of the rest of the body. Meniscus tears can happen when twisting while bearing weight.

Exercise is good for people of all ages. It helps lower blood pressure, reduces the risks for falls and serious injuries, and slows the body's loss of muscle and bone mass.

Your neck is at risk for injury because of its location and range of motion. Neck pain can be caused by injury, age, or inflammatory disorders.

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

Arthritis and other rheumatic diseases are common conditions that cause pain, swelling, and limited movement. They affect joints and connective tissues around the body. Millions of people in the U.S. have some form of arthritis.

Because most mouths are too small for the 4 additional molars called wisdom teeth, these teeth usually must be removed. Here's how it's done.

Cirrhosis is when scar tissue replaces healthy liver tissue. This stops the liver from working normally.

Toxic shock syndrome (TSS) is a cluster of symptoms that involve many systems of the body. Certain bacterial infections release toxins into the bloodstream. These toxins can spread to many body organs. This can cause severe damage and illness.

Rubella is sometimes called German measles. It is a viral infection. It usually causes a mild illness in children. Adults have a slightly more severe illness.

Poliomyelitis is commonly called polio. It is an infectious disease. It is caused by 3 types of poliovirus. Polio is easily spread from person to person. The poliovirus is a virus that causes paralysis. But most people who are infected with polio have no symptoms and a few have mild symptoms.