Patients whose feet are inexplicably swollen and painful should consider the following causes: first, acute dorsal foot sprain: a lot of and excessive sports can lead to strain on the dorsal fascia and soft tissues of the foot, so swelling and pain in the dorsal foot may occur. Second, varicose veins in the lower extremities: at this time, the venous valve function is often defective, resulting in restricted blood return to the lower extremities, which can cause blood to pool in the foot when walking excessively, and it is difficult to return, so it can manifest as a feeling of swelling and swelling of the foot. Third, cardiac insufficiency: When cardiac insufficiency occurs, sunken edema of both lower limbs will appear.