If the joint is swollen, in the case of osteoarthritis in the elderly, a joint puncture will be performed to extract the fluid, and then a joint flush will be performed to flush out the inflammatory factors and pain-causing substances in the joint, along with some anti-inflammatory and pain-relieving drugs. If the results are not satisfactory, minimally invasive arthroscopic surgery can be performed to remove the synovial membrane that has grown inside the joint. After the swelling has subsided, joint replacement surgery can be performed at a later date. In case of rheumatoid arthritis, appropriate rheumatoid treatment will be given. If the results are not satisfactory, minimally invasive arthroscopic surgery can be performed to clean up the synovial membrane, and patients with advanced disease will require artificial joint replacement. For septic joint infection, joint irrigation should be performed as soon as possible and treated with antibiotics at the same time. If the treatment is effective, the joint can be flushed several times and treated with antibiotics for a long time. If the treatment is unsatisfactory, surgery should be performed as early as possible, either arthroscopic surgery or incisional surgery, during which the pus is cleaned up and a cannula is flushed at the same time. Tuberculosis is mainly treated with tuberculosis medication, but it is very difficult to confirm the diagnosis of tuberculosis, so you can try it by trying anti-tuberculosis medication for a period of time, and if it is effective, then continue, and if the treatment is not effective, stop using anti-tuberculosis medication and consider other causes. For some unexplained joint effusion, you can also do arthrocentesis, use anti-inflammatory and pain-relieving drugs, do joint irrigation, etc.