The specific causes of swelling of the right ankle are as follows: 1. old ankle sprain: after ankle sprain, the symptoms of ankle swelling can be left behind. 2. arthritis: when the ankle joint is arthritic due to osteoarthritis or rheumatoid rheumatism, it can lead to swelling of the ankle joint. blood tests, X-rays and CT examinations should be performed to make a diagnosis. 3. 3. Gout: Pain in the ankle joint can be accompanied by swelling and limitation of joint movement, and blood uric acid should be checked for diagnosis and treatment with uric acid-lowering drugs. 4. Tumor: If there is tumor growth in the bone, synovium or soft tissue of the ankle joint, there can be swelling, pain and limitation of ankle movement, and MRI should be performed for diagnosis and treatment.