The swollen feet have pits when pressed down, depending on whether the swollen feet are swollen on one side or both sides. If there is a pit when you press down, it depends on whether it can be relieved when you wake up. If the feet are swollen on both sides, we should suspect whether it is caused by internal diseases, such as poor heart function, poor kidney function, or hypoproteinemia due to liver disease, which may cause bilateral foot swelling. It is also necessary to rule out the possibility of hypothyroidism, which can cause bilateral swelling of the feet. If the foot is swollen unilaterally, it should be suspected that it is related to the poor venous return of the lower limbs, and if the foot is empty for a long time, it will also be swollen, which is directly related to the venous insufficiency of the lower limbs.