Tennis elbow may cause certain local as well as systemic side effects if it is treated with frequent and repeated closed injections. Tennis elbow, also known as lateral epicondylitis of the humerus, is caused by aseptic inflammation of the extensor tendon of the forearm due to repeated pulling and irritation of the stopping point of the extensor tendon of the forearm, resulting in pain on the lateral side of the elbow joint, which affects elbow joint function. Closure therapy is a treatment for tennis elbow. By injecting a small amount of hormone and local anesthetic into the local area, it can reduce the local edema and inflammation stimulation, so as to reduce the local pain and restore the function of the elbow joint, and infrequent injection of closure is generally without side effects. However, if the same part of the closed injection is repeated several times in a short period of time, it is easy to cause the tendon or some ligament tissues at the injection site to become brittle and thus rupture, and diabetic patients may cause transient elevation of blood glucose, and repeated injections are also prone to cause local infections. Therefore, if you have tennis elbow, you must go to a regular hospital, follow the doctor’s instructions for treatment, do not do it yourself, so as not to delay the condition. The medication should be applied according to the doctor’s prescription.