Leg swelling a press a pit consider lower extremity vascular valve closure insufficiency, nephrogenic disease, cardiogenic disease, pulmonary disease, hepatic disease, lower extremity venous thrombosis. 1. Lower extremity vascular valve closure insufficiency: swelling of the lower extremities can occur, this is because of frequent standing for a long time caused by blood stagnation in the lower extremities, so there will be swelling, bed rest and elevation of the lower extremities can disappear, through the lower extremity ultrasound can be a clear diagnosis of the blood vessels, wear medical compression stockings can prevent the swelling of the lower extremities. 2. Nephrogenic diseases: such as nephritis, nephrotic syndrome can appear lower limb swelling, usually both sides are swollen, through the laboratory tests of renal function and urinalysis can assist in the diagnosis, and can be alleviated through drug treatment. 3. Cardiogenic diseases: such as cardiac insufficiency caused by bilateral lower extremity edema, accompanied by chest tightness, panic. 4. Diseases of pulmonary origin: e.g. emphysema, pulmonary heart disease with cough and shortness of breath. 5. Hepatogenic diseases: e.g. cirrhosis, hepatocellular carcinoma combined with hypoproteinemia. 6. Lower extremity venous thrombosis: swelling of the lower extremities, accompanied by swelling and pain, lower extremity vascular ultrasound can be clearly diagnosed. The above reasons are the causes of lower limbs a press a pit, need to be examined in the hospital to clarify, for the cause of the treatment.