Knee pain can be caused by the following: 1, osteoarthritis, osteoarthritis is often due to degeneration in the elderly, or after a traumatic fracture of the knee joint, resulting in traumatic osteoarthritis, when the knee joint pain can occur, serious cases will be accompanied by joint deformity and joint movement is obviously limited, the need for X-ray examination diagnosis and treatment. 2, synovitis, synovitis can appear knee pain, often due to cold or strain, physical therapy and oral medication to diagnose and treat. 3. Gout or rheumatic diseases, rheumatoid diseases that lead to knee pain, to be diagnosed by blood tests. 4. Tumors of the knee joint, tumors of the knee joint tibia, femur and synovial membrane of the knee joint, can appear knee pain, to be diagnosed and treated by X-ray and MRI of the knee joint. X-rays and nuclear magnetic examinations of the knee joint are required for diagnosis and treatment.