What Is Tennis Elbow?

Repeated twisting of a screwdriver can cause problems over time.

Tennis elbow (also called lateral epicondylitis) is an inflammation around the bony knob (lateral epicondyle) on the outer side of the elbow. It occurs when the tissue that attaches muscle to the bone becomes irritated.

Your Lateral Epicondyle

The muscles that allow you to straighten your fingers and rotate your lower arm and wrist are called the extensor muscles. These muscles extend from the outer side of your elbow to your wrist and fingers. A cordlike fiber called a tendon attaches the extensor muscles to the elbow. Overuse or an accident can cause tissue in the tendon to become inflamed or injured.

Causes

Playing a racket sport can cause tennis elbow. So can doing anything that involves extending your wrist or rotating your forearm—such as twisting a screwdriver or lifting heavy objects with your palm down. With age, the tissue may become inflamed more easily.

Symptoms

The most common symptom of tennis elbow is pain on the outer side of the elbow and down the forearm. You may have pain all the time or only when you lift things. The elbow may also swell, get red, or feel warm to the touch. And it may hurt to grip things, turn your hand, or swing your arm.