Swollen legs and feet are mainly caused by cardiac insufficiency, renal insufficiency, hepatic insufficiency, venous insufficiency of the lower limbs, etc., as follows: 1. Cardiac insufficiency: Cardiac insufficiency is often manifested as swollen legs and feet of both lower limbs, in addition to coronary heart disease, hypertension and other heart-based diseases, often manifested as bad heart performance such as breathing difficulties after exertion. 2. Renal insufficiency: Renal insufficiency Patients often have swollen legs and feet of both lower limbs, which is one of the most common causes. In addition to swollen legs and feet, there will also be positive urine protein, as well as chronic kidney disease, renal insufficiency and other manifestations. 3, liver insufficiency: patients with liver insufficiency often have a history of cirrhosis, and there will also be symptoms of the digestive system. 4, lower limb venous insufficiency: lower limb venous insufficiency can be manifested as simple leg and foot swelling, but also can be manifested as double leg leg swelling, in this case need to Avoid sitting and standing for a long time, and put your legs up when you rest. Therefore, if swollen legs and feet occur, the cause needs to be analyzed according to the patient’s specific situation and then treated symptomatically.