A small amount of effusion in the leg joint can be treated as follows: First, avoid getting cold or excessive exercise, because cold and excessive exercise can cause damage to the synovial membrane of the knee joint, thus making it acutely aggravated and leading to an increase in the amount of effusion. Second, physical therapy, microwave physiotherapy or far-infrared physiotherapy can be used for the treatment of knee effusion to promote the absorption of synovial inflammation and reduce synovial exudation, which can also reduce the amount of effusion. Third, oral medication can be taken orally for pain relief such as meloxicam, celecoxib, and loxoprofen sodium tablets, as well as oral Chinese medicines for synovitis such as synovitis tablets. If there is a primary disease such as osteoarthritis, gout or tuberculosis, rheumatoid, the primary disease should be treated accordingly so that the fluid can be better absorbed early and the symptoms of joint pain and swelling can be relieved and disappeared early.