The most common case is poor circulation in the lower extremities, such as vascular atherosclerosis, vascular stenosis, or even blockage, which can cause edema caused by poor circulation in the lower extremities, especially after a long walk and a long stand, which can easily appear in the afternoon and evening, and may disappear on its own in the morning of the second day, and in this case, you can massage the back of the foot for the elderly. If you encounter this situation, you can massage the back of the foot, or take some drugs to activate blood circulation and improve microcirculation. Another condition is more common in heart failure, where swelling of both lower extremities may occur, but it may be accompanied by panic, chest tightness, wheezing and other manifestations of heart failure. The third condition, edema of the feet, can be seen in hypoproteinemia. Patients with hypoproteinemia, malnutrition edema, may also have swelling of the whole body or feet. Patients with hypothyroidism may also have generalized or bilateral non-sunken edema of the lower extremities. In addition to edema of the lower extremities, patients with renal failure may also have swelling of the eyelids, proteinuria, hematuria, and anemia, which also need to be examined in the hospital for a clear diagnosis.