Calf edema during the daytime may be caused by varicose saphenous veins and venous blood stasis. 1. Varicose saphenous vein: Varicose saphenous vein is mostly seen in the working group who stand for a long time during the daytime, which usually leads to the obstruction of venous blood return and stagnation in the blood vessels of the lower limbs, and then edema of the lower legs may occur. When you sleep at night, you need to lie down, the blood flow in the lower limbs will be smooth, and the edema will disappear, so the daytime edema of the calf will disappear after a sleep. 2. Venous blood stagnation: when the human body is standing or squatting for a long time, the veins of the lower limbs are in a state of blood stagnation, which leads to elevated venous pressure, and the venous blood penetrates into the subcutaneous tissues through the walls of the blood vessels, resulting in leg edema. Especially during the daytime, this symptom of calf edema can be aggravated. At night when you sleep, by elevating the calves you can reduce the pressure in the veins and reduce the venous blood stagnation, which will make the symptoms of calf edema disappear. If the patient’s calf edema every day during the day after sleeping, it is recommended to consult a doctor in time to identify the cause of the disease, according to the cause of targeted treatment.