The dorsum of the foot is swollen and painful for no reason, the following diseases are mainly considered: 1, vascular diseases of the lower limbs, such as varicose veins of the lower limbs, due to venous valve insufficiency, which often causes the patient’s feet and calves to restrict the blood flow, and a large amount of blood will be stagnant in the feet. As a result, there will be swelling and pain on the back of the foot, especially when walking too much, there will be a feeling of foot and calf swelling.2. There may be deep vein thrombosis of the lower limbs, when thrombosis will cause obstruction of blood return in the lower limbs, which will also cause pain and swelling in the foot and calf.3. It is necessary to consider cardiovascular disease or chronic renal disease, for example, in the case of cardiac insufficiency, it may cause double lower extremity depression edema, and in the case of renal insufficiency, there will also be limb pain and swelling.4. In renal insufficiency, edema of the limbs may also occur.