If a patient has swelling of the lower extremities, the differential diagnosis is usually made mainly from liver function, kidney function, thyroid function and cardiac function, and the actual clinical symptoms of the patient should also be taken into account, such as whether the patient has any difficulty in breathing, shortness of breath, or any previous history of cardiovascular disease when swelling of the lower extremities is present, and if so, the current swelling of the lower extremities is highly considered to be due to If so, it is highly considered that the current lower limb swelling is caused by heart failure. If the patient is a tumor patient and has recently eaten poorly and is in a cachectic state, it is likely that the swelling of the lower extremities is due to hypoalbuminemia. If the patient has weakness, constipation, or slow heart rate, the first thing to rule out is whether the swelling is due to hypothyroidism.