There are many causes of lower limb edema, and the cause should be clarified and treated for the cause. The main causes of lower limb edema are heart failure, renal disease, liver cirrhosis, endocrine, local limb vascular and lymphatic circulation disorders and local limb inflammatory factors. 1, heart failure: diuretics such as furosemide, hydrochlorothiazide and other drugs and cardiac drugs, vasodilator drugs can improve heart failure, and lower limb edema can be eliminated after heart failure is relieved. 2, nephritis and nephropathy, etc.: sodium and water retention is the underlying mechanism of edema in nephritis and nephropathy. In the application of immunosuppressants for etiological treatment at the same time, diuretics can be applied for symptomatic diuresis to reduce edema, while plasma or albumin can be infused to improve plasma colloid osmotic pressure and reduce edema. 3.Cirrhotic decompensation stage: the cause of edema caused by cirrhosis is the combined effect of hepatic decompensation and portal hypertension, which can be diuretic or plasma infusion to enhance the albumin content. At the same time to apply drugs to protect liver function. 4, endocrine factors: such as hypothyroidism, hyperthyroidism, Cushing’s syndrome, etc. can be treated for the cause. 5, local factors: lymphatic reflux disorder edema, venous reflux disorder edema can be treated with drugs combined with surgical treatment. Inflammatory edema can be treated with anti-infection therapy. 8. Physiological edema factors: such as high temperature, edema caused by pregnancy, premenstrual tension syndrome, and sedentary can cause lower limb edema. The edema can disappear after the cause is lifted.