Epicondylitis is an inflammation or damage to the area of an epicondyle of bone. An epicondyle is a projection of bone above a condyle (a rounded prominence at the end of a bone, usually where the bone connects to another bone) where ligaments and tendons are attached. Two common types of epicondylitis are tennis elbow and golfer's elbow. Tennis elbow is also known as lateral epicondylitis, which is an overuse injury to the area of the lateral (outside) epicondyle of the elbow end of the upper arm bone (humerus). Golfer's elbow (medial epicondylitis) is an overuse injury similar to tennis elbow, but in this case the damage occurs in the area of the medial (inside) epicondyle of the upper arm bone.