What is alopecia areata? Alopecia areata is a disease that causes hair loss. In alopecia areata, the immune system attacks the structures in skin that form hair (hair follicles). Alopecia areata usually affects the head and face, though hair can be lost from any part of the body. Hair typically falls out in small, round patches about the size of a quarter. In some cases, hair loss is more extensive.
What is back pain? Back pain is one of the most common medical problems in the United States. It might feel like a dull, constant ache or a sudden, sharp pain. Back pain can result from: An accident. A fall. Lifting something heavy. Changes that happen in the spine as you age. A disorder or medical condition. Treatment depends on the cause and symptoms of your pain. You can do things to improve your health and lower your chance of developing chronic (long-lasting) back pain.
What are sports injuries? Sports injuries are injuries that happen when playing sports or exercising. There are two kinds of sports injuries: Acute injuries occur suddenly when playing or exercising. For example: Sprained ankles. Strained backs. Broken bones. Chronic injuries happen after you play a sport or exercise for a long time.
What are sports injuries in youth? Although sports injuries can range from scrapes and bruises to serious brain and spinal cord injuries, most fall somewhere between the two extremes. Here are some of the more common types of injuries: Muscle sprains and strains. Injuries of a growth plate, area of tissue at the end of the long bones in growing children and teens. Injuries from overuse of muscles and tendons. Learn more about sports injuries.