The leg deficiency is a pit when pressed, which means the leg is edematous, and this edema is often depressed. The causes of leg edema are divided into two cases, one is unilateral leg edema, including venous obstruction, tissue inflammation, and the other is bilateral leg edema, including malnutrition, heart disease, etc. One, unilateral leg edema causes: 1, venous obstruction: phlebitis, deep vein thrombosis and many other reasons can lead to the appearance of venous obstruction, thus causing unilateral leg edema, appearing a press a pit; 2, tissue inflammation: such as cellulitis, patients can show unilateral leg inflammatory edema, appearing a press a pit, may also be accompanied by fever, pain and other symptoms. Second, bilateral leg edema causes: 1, malnutrition: mostly seen in patients with partial diet or chronic wasting diseases, resulting in a decrease in the body nutrients plasma albumin, a decrease in plasma colloid osmotic pressure, easily cause bilateral leg edema, a press a pit, but also can show anemia, hypoproteinemia and other clinical features, edema before there is more wasting, weight loss, anemia, weakness and other pre-performance; 2, heart disease: such as heart right heart failure, can appear edema symptoms, a press a pit. Usually appear first on the inner side of the ankle, mild edema is obvious after activity, reduce or disappear after rest, serious will develop upward to the whole body edema, while the patient will be accompanied by chest tightness, shortness of breath, dyspnea and other symptoms; 3, liver disease: patients with a previous history of liver disease, usually the edema first appears in the ankle, then spread upward, appear a press a pit, can also be accompanied by weakness, loss of appetite, jaundice, spider nevus, etc.; 4, the Kidney disease: edema often appears first in the eyelids and facial area, and after the condition worsens, edema of the lower extremities may appear, with a single press a pit, and edema of kidney disease may also be accompanied by oliguria, hematuria, foamy urine, anemia, hypertension, etc.; 5. Other causes: such as rheumatic system diseases, etc., involving the kidney heart may also cause edema of both lower extremities.