Tennis elbow or lateral epicondylitis is a painful condition of the arm. It is caused by repetitive trauma to the tendons of the forearm. The arm is made up of three bones; the humerus ( arm bone), radius and ulna( bones of forearm). There are several bumps on the humerus called epicondyles. The bump on the outside of the humerus is the lateral epicondyle. The pain of tennis elbow is localized to the lateral epicondyle. Several mechanisms can cause tennis elbow including repetitive motions such as shaking hands, scooping ice cream or tennis (of course). Painters, plumbers and cooks also get tennis elbow frequently. It is made worse with activity. Sleep disturbance is very common. There is tenderness along the side of the arm and below the elbow on the outside. Grip strength may be diminished. Arthritis, tendonitis and gout may also be associated with tennis elbow. A nerve test, the EMG and Nerve Conduction study, can differential tennis elbow from other causes of arm pain such as a herniated or bulging cervical disc. Plan X-rays can exclude other causes, such as fractures. Radial tunnel syndrome and cervical disc problems can mimic this problem as well. Treatment of tennis elbow includes rest, physical therapy, non-steroidal anti-inflammatories and the local application of heat and ice. Injection of the lateral epicondyle with a solution of a local anesthetic and a steroid is also useful.