What is tendinitis? Tendinitis is swelling and pain in a tendon, which is tissue that connects muscles to bones. It is a common condition, usually caused by repeated injuries to a tendon.
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.