The causes of leg and face swelling: 1. It may be a transient swelling. For example, swelling can occur after drinking a lot of water the night before or staying up late. 2. Idiopathic swelling. The cause of swelling in these patients is not very clear, and it can often be relieved after rest. 3. Some pathological causes. For example, kidney disease, liver disease, heart disease and endocrine system diseases can cause swelling of legs and face. Kidney diseases, such as glomerulonephritis and renal insufficiency, can cause swelling of the legs and face. Patients will initially show puffiness of both eyelids or facial swelling, and as the disease worsens, swelling of the whole body will appear. In addition to edema, patients with heart disease may also suffer from panic attacks, chest tightness and dyspnea, often seen in patients with heart failure. Patients with liver disease, especially those with liver failure, have hypoproteinemia due to reduced albumin synthesis, which in turn induces swelling of the legs and face.