Elderly knee swelling and pain, the following reasons are common: First, degenerative osteoarthritis and synovitis of the knee: this is the most common cause of knee swelling and pain in the elderly, mainly related to age factors, patients with long-term overweight and degeneration, which can lead to swelling and pain in the joints, accompanied by joint activity restrictions, and in severe cases, accompanied by a large amount of joint effusion, which can be confirmed by magnetic resonance imaging examination. Diagnosis can be confirmed by MRI. Secondly, knee trauma: the muscle strength of lower limbs of elderly patients will be significantly weakened, if they carry out sports, knee injuries are likely to occur, resulting in knee swelling, pain and other symptoms, and can be accompanied by limited knee activities, X-ray film can be found to be fracture dislocated, and MRI filming can be found in meniscus injuries, ligament injuries. Through early diagnosis and early treatment, the symptoms of knee swelling and pain in elderly patients can be relieved quickly and serious complications can be prevented.