Suddenly gained weight, suggesting lower limb edema. The causes of lower limb edema can be clinically seen in kidney disease, heart disease, liver disease and thyroid disease. Kidney disease, such as nephritis, nephrotic syndrome, etc., it is recommended to further check the blood routine, urine routine, ionized kidney function, 24hUP quantification to clarify the diagnosis, and apply immunosuppressant treatment if necessary. If it is caused by cardiac insufficiency, foot edema will be aggravated after activity, and can be intermittently applied with cardiac nutritive drugs and diuretics for symptomatic treatment. If it is caused by liver disease, it is usually caused by the decrease of albumin synthesis, which leads to the decrease of plasma colloid osmotic pressure and causes edema, and the intermittent infusion of albumin is effective for the disease. If caused by thyroid function, it is recommended to actively supplement thyroid hormone and treat the primary disease.