Swelling and pain in the knee of the elderly, the following common causes: First, degenerative osteoarthritis and synovitis of the knee: this is the most common cause of swelling and pain in the knee of the elderly, mainly related to age factors, the patient long-term excessive weight bearing and degeneration, can lead to joint swelling and pain, accompanied by joint movement restrictions, and in severe cases will be accompanied by a large amount of joint effusion, can be confirmed by MRI The diagnosis can be confirmed by MRI. Secondly, knee trauma: the muscle strength of the lower limbs of elderly patients will be significantly weakened, and if sports are performed, knee injury will easily occur, resulting in swelling and pain of the knee joint and other symptoms, and can be accompanied by limited movement of the knee joint. Early diagnosis and treatment can provide rapid relief of swollen and painful knee symptoms in elderly patients and prevent serious complications.