The more common causes of calf swelling are infection, soft tissue injury, varicose veins of the lower limbs, venous thrombosis, renal disease and cardiovascular disease disease, etc., which require timely consultation to identify the causes. 1. Infection: cellulitis and dengue are common, due to infection, resulting in increased tissue exudation, affecting blood circulation, which can easily cause swelling of the lower legs. 2. Soft tissue injury: when the soft tissue of the calf is injured, there will be obvious exudation, which affects the venous blood return and leads to swelling of the calf, mostly accompanied by chronic pain. 3. Varicose veins of the lower limbs: the most common is varicose veins of the saphenous vein, which affects the venous blood return and leads to poor circulation, thus causing swelling of the calves, partly accompanied by hyperpigmentation, ulceration, and so on. 4. Venous thrombosis: when thrombosis occurs in the veins of the lower limbs, it affects the return of venous blood, resulting in obvious swelling of the calves, which is recurrent and partly accompanied by changes in skin temperature. 5. Kidney disease: the more common is chronic glomerulonephritis, the decrease of albumin in the blood as well as the decrease of kidney’s filtration function, which causes the increase of exudation of calf tissues and the occurrence of edema. 6. cardiovascular disease: common is chronic heart failure, and venous blood back to the heart is blocked, resulting in poor circulation, thus causing calf swelling. In summary, there are many reasons why calves are prone to swelling, through rest and self-conditioning can not be improved, you should consult a doctor in a timely manner to identify the causes and standardize treatment to avoid delays in the condition.