Repeated symptoms of foot edema in a 77-year-old man may be caused by heart disease, malnutrition, lower extremity venous thrombosis, kidney disease, hypothyroidism, etc., and further examination is needed to confirm the diagnosis. 1. Heart disease: such as pulmonary heart disease, acute and chronic heart failure, right heart insufficiency, due to the restriction of venous return flow, symptoms of lower extremity edema can occur, can be accompanied by dyspnea and other symptoms, can check the heart function to confirm the diagnosis. 2. Malnutrition: such as hypoproteinemia, anemia, etc., can also cause edema of the feet, and in severe cases, the symptoms of generalized edema can occur. 3. Lower extremity venous thrombosis: when lower extremity venous thrombosis, due to the obstruction of venous return in the lower extremity, the symptoms of edema of one or both lower extremities may appear, and the diagnosis can be confirmed by checking the vascular ultrasound of the lower extremity. 4. Kidney disease: such as nephrotic syndrome, acute and chronic renal failure, etc., may be accompanied by facial edema, proteinuria, hematuria and other symptoms, you can check the urine routine, renal function and other clear diagnosis. 5. Hypothyroidism: it is caused by the low secretion of thyroid hormone, and may appear edema, slow heart rate and other symptoms. Thyroid function test can be clear. When edema occurs repeatedly in the elderly, further examination is needed to clarify the diagnosis and then carry out targeted treatment.