Swelling of the face and legs can be caused by the following diseases: First, patients with advanced malignant tumors, due to disorders of the internal environment, anemia and hypoproteinemia, the colloid osmotic pressure of plasma decreases, leading to leakage of tissue fluid into the tissue, a common symptom is edema of the limbs. Secondly, due to diseases of the renal system, patients with renal insufficiency have an imbalance of water and sodium metabolism, which can also lead to fluid retention, which can manifest as reduced urination, and in severe cases, acute renal failure can also occur. Mild patients can be given appropriate diuretic therapy, the patient’s symptoms can be improved.