Clinically, the common causes of swelling but no pain in one side of the ankle are physiological swelling, deep vein thrombosis in the lower limb, superficial varicose veins in the lower limb, chronic strain on the ankle joint, heart failure, and renal insufficiency. 1. Physiological swelling: Most of them are due to the obstruction of lower limb venous return caused by long-term standing, resulting in swelling of one side of the ankle, but without pain. The treatment is mainly to elevate the affected limb at rest, apply local heat and massage, and wear elastic stockings to protect the lower limb when standing; 2. The main treatment is vascular intervention, together with anti-thrombotic drugs, such as rivaroxaban; 3. Superficial varicose veins of the lower limbs: Most of them are caused by the incompetence of the valves of the superficial veins of the lower limbs, which can cause the superficial veins to stagnate and expand when the limbs are sagging, resulting in the swelling of one side of the ankle but without pain. Treatment is mainly to elevate the affected limb and wear elastic stockings for protection, but also through surgical treatment, which can be performed under the guidance of a doctor to ligate the varicose veins in high position and peel them off. 4. Chronic strain of ankle joint: Most of them are caused by chronic strain and edema of local tissues due to long-term strain and cold on one side of the ankle, resulting in local swelling, but there is no obvious pain because the damage is not serious. The main treatment is to elevate the affected limb, local hot compress and baking electric physiotherapy, which can be combined with massage and tui-na treatment; 5. Heart failure: when heart failure occurs, it can cause bruising of body circulation, resulting in swelling of one side of the ankle, but without pain. The main treatment is swelling medication, commonly used drugs are furosemide, spironolactone, etc.; 6, renal insufficiency: when renal insufficiency occurs, it can cause water and sodium retention, resulting in edema in the foot and ankle and eyelid, the main treatment is to reduce swelling and improve renal function, commonly used drugs are furosemide, etc.; 7, hypoproteinemia: when patients have hypoproteinemia, it may also lead to edema, which can be manifested as one side Patients can follow medical advice to use lamivudine to relieve symptoms; 8. Malnutrition edema: Patients with malignant malnutrition may also lead to edema. At this time, patients can follow medical advice to supplement nutrients, such as glucose, which can alleviate the symptoms to some extent. In daily life, if you have swelling and pain on one side of the ankle, please go to the hospital for examination in time to avoid delaying the disease and aggravating the symptoms.