There are three main causes of leg and foot edema in the elderly; first, heart failure; second, kidney; and third, low protein. Heart failure can cause increased pressure in the veins, and increased pressure in the veins will cause the water in the veins to flow out to the tissues, causing tissue edema, including leg and foot edema. Poor renal function, resulting in reduced water and sodium discharge from the body, sodium retention will cause increased water in the blood vessels and tissues, resulting in edema. Renal and hepatic insufficiency, easy to cause low protein, as well as low-protein consumptive diseases, such as increased ascites, will also cause the body low protein, low protein when the intravascular colloid osmotic pressure is reduced, easy to make the water in the blood vessels to the tissues, resulting in leg and foot edema phenomenon. The above content is for reference only, the specific medication, treatment, please be guided by the doctor’s interview shall prevail.