Gout can be caused by the following reasons: First, gout. When gout is involved in the ankle, there can be pain on one side of the ankle, accompanied by swelling and redness of the skin, and in serious cases, gout stones can be formed, and blood uric acid should be checked and x-ray of the ankle should be taken for diagnosis and treatment. Second, cysts, when there is a cyst in the lateral joint of the ankle or tendon sheath, there can be pain on the lateral side of the ankle, then ultrasound and MRI of the ankle joint should be checked for early diagnosis. Third, tendinitis, when the tendons around the ankle joint have tendinitis, there can also be pain on the lateral side of the ankle joint, so it is necessary to check the body early and check the MRI early to diagnose and treat.