The symptoms of swelling and pain in the unilateral ankle joint are commonly caused by the following: 1. acute injury, such as acute sprain during sports, daily work or labor, which can lead to local injury, resulting in swelling and pain; 2. chronic strain injury, such as certain types of work that require frequent activities of the ankle joint of one side of the limb and heavy load, which can lead to corresponding strain injury, which can lead to 3. The blood circulation of the ankle joint is abnormal, such as cold, vasculitis or varicose veins, which leads to the obstruction of blood flow in the local veins, resulting in swelling and pain; 4. Some tumors in the ankle joint, due to tumor erosion of bone and compression of local tissues, will lead to obstruction of blood flow, resulting in swelling and pain; 5. Other common ankle arthritis, such as rheumatoid arthritis, rheumatoid arthritis and ankle synovitis, will also lead to corresponding inflammatory reactions, swelling and pain.