The causes of edema are divided into physiological and pathological. 1. Physiological edema: if you drink too much water before going to bed, or long-term malnutrition, or in the middle and late stages of pregnancy, etc., it may lead to edema, but these causes of edema are physiological edema. 2. Pathological edema: pathological edema includes cardiogenic edema, hepatic edema, and nephrogenic edema. Cardiogenic edema is mainly seen in hypertension, heart failure, pericarditis and so on. Hepatogenic edema is mainly related to acute hepatitis, cirrhosis, hepatocellular carcinoma and so on. Nephrogenic edema is mainly related to glomerulonephritis, nephrotic syndrome, renal arteriosclerosis and so on. Physiological edema generally do not need special treatment, but pathological edema need to go to the hospital in time, to clarify the type of edema, and then accept the doctor’s targeted treatment.