The common causes of pain in the ankle joint with no obvious cause are as follows: first, caused by chronic strain, such as patients standing or walking for long periods of time or frequently performing physical exercise of the lower extremities, resulting in ankle joint involvement injury, which produces pain. Second, ankle synovitis, inflammation of the synovial membrane leading to pain, often accompanied by joint swelling, joint effusion, etc. Third, bone changes in the ankle joint, including infection, bacterial infection or tuberculosis infection, with significant local swelling and pain. Fourth, gouty arthritis, patients with gout, when there are adverse factors to stimulate, such as minor injuries, cold, etc., will lead to uric acid crystals deposited around the ankle joint, resulting in painful symptoms.