There are many causes of simple dorsal foot edema. First, the more common one is nephrogenic edema caused by kidney disease, such as nephrotic syndrome or nephritis syndrome. The diagnosis can be confirmed by performing tests such as urinary routine, liver and kidney function, and 24hUP quantification. Second, cardiogenic edema. Cardiogenic edema can be detected by cardiac ultrasound examination. Third, hepatogenic edema caused by liver disease. It can be detected by liver ultrasound and liver function tests. Fourth, edema of endocrine origin, such as hyperthyroidism or hypothyroidism, can be detected by rechecking the thyroid function. Fifth, localized vascular embolism can be diagnosed by examining the arteriovenous ultrasound of both lower extremities. If these conditions are ruled out, it may be idiopathic edema, which has no special treatment and does not require special treatment, and can be observed regularly.