Sudden joint pain, mainly consider the following causes: 1, synovitis, common in the knee joint, elbow joint, easy to attack after cold or exertion, manifested as sudden joint pain, soreness and swelling discomfort, accompanied by partial effusion, knee joint activity is limited, mainly due to cold synovial ischemia, hypoxia, and aseptic inflammation, through hot compresses, rest, and oral meloxicam and other non-steroidal The meniscus is a normal structure in the knee joint, which suddenly tears during walking, resulting in knee pain, edema, and severe activity limitation. 3, gouty arthritis, common in patients with increased blood uric acid, especially after eating purine-containing foods, blood uric acid This is a gouty arthritis that occurs when crystals are deposited in the joints after eating purine-containing foods, and is characterized by sudden joint pain, redness, swelling, and discomfort. 4.