The onset of this disease is mostly slow. At the beginning of the symptoms of tennis elbow, the patient only felt difficulty in swelling the outside of the elbow joint and slight pain. Patients feel pain in the upper elbow joint, which sometimes radiates upward or downward, feeling sore and uncomfortable and unwilling to move. You can't take things with your hands. Holding a shovel, carrying a pot, twisting a towel and knitting a sweater will aggravate the pain. Generally, there are localized tenderness points at the lateral epicondyle of humerus, sometimes the tenderness can be released downward, and sometimes there are mild tenderness and active pain even on the extensor tendon. There is no redness and swelling locally, and the flexion and extension of elbow joint are not affected, but there may be pain when forearm rotates. In severe cases, it can cause pain when fingers are straight, wrists are stretched or chopsticks are held. When the affected limb is in the elbow flexion forearm supination position, the extensor is in a relaxed state, so the pain is relieved. A few patients feel that their pain is aggravated in rainy days. Tennis elbow can be treated with traditional Chinese medicine plaster. Traditional black plaster Zhao's health care plaster is a traditional Chinese medicine product specially used for treating tennis elbow, which has achieved good results in treating tennis elbow.