The most common cause of swelling in the lower legs due to prolonged standing is venous valve insufficiency of the lower extremities, but it is also necessary to exclude the causes of kidney, heart, thyroid and liver diseases. The most common cause of swollen calves due to prolonged standing is venous valve insufficiency of the lower extremities. The veins in the lower extremities have a venous valve that is designed to stop the reflux of blood that has already returned. If this valve is not functioning, it will cause blood to flow back and will cause swelling in the lower legs, and in this case, ultrasound of both lower extremities can be performed. In addition, other causes of calf swelling should be excluded, such as nephritis, nephrotic syndrome, liver cirrhosis, right heart failure, hypothyroidism and so on. In addition to swelling in the lower legs, these diseases may also cause edema in other areas, such as eyelid edema and facial edema, so urine routine, liver and kidney function, thyroid function and cardiac ultrasound may be performed.