Elderly people with swollen legs need to check liver and kidney function. Common causes of lower limb edema include hypoproteinemia and renal insufficiency. 1. Hypoproteinemia: Older people may suffer from malnutrition due to low food intake, poor intestinal absorption or other consumptive diseases (such as tumors, tuberculosis, etc.), resulting in hypoproteinemia, which can lead to swelling of the lower limbs and even the whole body, and may be accompanied by symptoms such as fatigue, and the liver function can assist in the definitive diagnosis. 2. Renal insufficiency: when renal insufficiency occurs, due to the decrease of glomerular filtration rate and fluid retention in the body, it can lead to edema of the lower limbs, and it can be accompanied by symptoms such as decrease of urine output and increase of blood creatinine and urea nitrogen level, so the renal function can assist in the clear diagnosis. Therefore, the elderly leg swelling need to check the liver and kidney function in order to clarify whether the problem of hypoproteinemia and renal insufficiency, in addition there may be other reasons, it is recommended that patients with swelling of the lower extremities to the hospital in time to improve the relevant examinations under the guidance of the doctor, in order to clarify the cause of the disease, timely treatment.