Swollen legs and feet in the elderly may be caused by prolonged standing or walking, kidney disease, liver disease and other reasons. 1. Standing or walking for a long time: due to the effect of gravity and the continuous tension of the muscles of the lower limbs, it will lead to the slowing down of blood reflux, causing the obstruction of venous blood reflux, and in the long run, the old people will have swollen legs and feet. 2. Kidney disease: When patients suffer from kidney disease, it will also cause swelling of legs and feet. Mainly because the kidneys are responsible for the metabolism of substances in the body, once the kidneys are abnormal, it is easy to cause water retention in the body, causing edema of the lower limbs. 3. Liver disease: the liver is the place where plasma protein is synthesized, if liver disease occurs, it will induce a reduction of protein in the plasma, resulting in body fluids staying in the interstitial space of the tissues, resulting in edema of the legs and feet. In addition to the above, there are other conditions that may lead to edema in the legs and feet of the elderly, such as heart failure edema, hypothyroidism edema, etc. If the symptoms do not improve after improving lifestyle habits, it is recommended to go to the hospital for an examination, and comply with the doctor’s instructions in a timely manner for targeted treatment to avoid delay in the course of the disease.