In tennis elbow (humeral epicondylitis), the tendon at the beginning of the forearm extensor muscle on the outside of the elbow joint becomes inflamed and painful. The pain is caused by a chronic tear and strain of the forearm extensor muscle caused by repetitive force. The patient may feel pain in the affected area when gripping or lifting objects with force. Tennis and badminton players are more common, and housewives, bricklayers, carpenters and others who repeatedly exert themselves for a long time to do elbow activities are also susceptible to this disease. 1, the cause of tennis elbow (1) hitting tennis incorrect technology, tennis racket size is not suitable or tennis racket line tension is not suitable, golf grip or swing technology is not correct, etc. (2) Excessive arm certain activities, such as tennis, badminton pumping, baseball pitching; other work such as painting, rowing, making a hammer or screwdriver, etc. (3) Actions often done in daily life, such as wringing towels, carrying water bottles, holding children, etc. can also trigger tennis elbow. 2, clinical manifestations Most of the disease is slow onset, the symptoms of tennis elbow at the beginning, the patient just feel the pain on the outside of the elbow joint, the patient feels pain from the activity above the elbow joint, the pain can sometimes be radiated upward or downward, feeling sore and swollen, reluctant to move. The pain can be aggravated by movements such as holding a shovel, lifting a jug, wringing a towel or playing a sweater. There is usually a limited pressure point at the lateral epicondyle of the humerus, and sometimes the pressure pain may spread downward, and there is even mild pressure pain and activity pain in the extensor tendon. There is no local redness or swelling, and elbow extension and flexion are not affected, but the forearm can be painful during rotation activities. In severe cases, pain can be caused when extending fingers, wrists or holding chopsticks. A few patients feel more pain when it is rainy or cloudy. 3, prevention and treatment recommendations Do not do or do less of a certain action that causes tennis elbow, to reduce the triggering factors; once the onset of the disease should be timely diagnosis and treatment, you can gradually get relief through internal medicine, external use, acupuncture, physical therapy and other methods; pay attention to protection on rainy days to avoid wind and cold; pay attention to prevention after healing to reduce the chances of recurrence.