Tennis elbow is painful weakening of the tendons that join your forearm muscles to your bones. It happens when you work your elbow too much by repeating certain motions. You might hear your doctor call it lateral epicondylitis.
Despite the name, tennis causes only about 5% of cases. You can get it after doing any kind of repetitive movement, like painting or using hand tools. Tennis elbow is a common injury that usually needs only minor treatment, but it takes time and rest to heal.
The pain is focused on the outside of your arm, where your forearm meets your elbow.
It’s related to a muscle and tendons in your forearm. Tendons connect your muscles to your bones. When you repeat certain arm movements, the tendons at the elbow end of a certain muscle — the extensor carpi radialis brevis (ECRB) muscle — may get small tears.
The tears may put stress on the rest of your arm, making it painful to lift and grip things. If you don’t get treatment, the pain can last a long time.
The most common symptom of tennis elbow is an ache on the outside of your elbow. Over time — from a few weeks to a few months — the ache turns into a constant pain. The outside of your elbow may be too painful to touch.
You can have tennis elbow in one or both arms.