It is not impossible to pump knee effusion, but it is necessary to determine the cause that triggered the knee effusion and the amount of effusion to be determined. Knee effusion can be caused by inflammatory lesions such as synovitis, osteoarthritis, trauma, etc. After inflammatory changes and trauma, synovial congestion, edema, and rupture of blood vessels can occur, followed by exudation to produce effusion, and the amount of effusion is related to the condition. The amount of effusion depends on the condition. When the effusion is found, treatment should be carried out according to the cause of the disease, and the exudation will be reduced gradually, and the effusion can be absorbed gradually, so there is no need to extract the effusion. If the amount of fluid is large and swelling occurs, limiting the movement of the joints, the doctor can extract the fluid by puncture. It is important to eat a healthy diet, keep your weight within a reasonable range, rest, and avoid repeated irritation of the joints.