Swelling of the extremities is commonly caused by hypoproteinemia, and severe heart failure, renal failure, etc., as follows: First, hypoproteinemia: if the patient eats poor nutrition, while the body consumption increases, such as the production of malignant tumors, can lead to hypoproteinemia. Patients will have obvious clinical symptoms such as swelling and pain in the extremities, accompanied by peripheral weakness and decreased immune function, which can easily lead to infection in body parts. Secondly, severe heart failure and renal failure: it will lead to increased intravascular fluid and vascular reflux obstruction, which will cause obvious swelling of the limbs, accompanied by circumferential weakness, chest tightness, panic, lumbar pain, abnormal urination and so on. Therefore, patients with swollen extremities should be diagnosed and treated early to avoid delaying the disease.