Tendonitis may be caused by endogenous factors, exogenous factors, etc. It is a sterile inflammatory reaction, and hospitalization is recommended. 1. Endogenous factors: pain and limitation of movement may occur due to degeneration and wear and tear of the tendon itself. 2. Exogenous factors: Prolonged and frequent mechanical flexion and extension movements are also prone to tendon strain. For playing tennis, swimming, golf and other people are more likely to suffer from tendonitis. Acute injury to the tendon may also occur due to incorrect training methods, overloading intensity, etc. Localized exudation and inflammatory reaction develop. Tendonitis is a kind of sterile inflammation, it is recommended to timely hospital for consultation, the doctor according to the condition, take the appropriate treatment plan.