Swelling of the face for no reason may be caused by nephrogenic edema, metamorphic edema, premenstrual syndrome and so on. 1. Nephrogenic edema: such as acute glomerulonephritis, nephrotic syndrome, chronic kidney disease and other kinds of nephritis and kidney disease, may lead to swelling of the face for no reason, usually accompanied by changes in urinary routine, hypertension and renal function impairment. 2. Metabolic edema: mainly considered with the skin, mucous membrane metabolic reaction, sensitization of the original pathogenic microorganisms, xenogeneic serum, certain foods and animal fur, etc., which can also lead to unexplained swelling of the face, usually accompanied by itching, pain and other sensory abnormalities. 3. Premenstrual syndrome: refers to women of childbearing age in the eyelids, ankles and hands edema 7 to 14 days before the onset of menstruation, which can also lead to unexplained swelling of the face, can be accompanied by breast distension, pelvic heaviness, edema gradually recede after menstruation. There are many other causes of swelling of the face for no reason, which should be taken seriously, timely consultation, identification of the cause of the disease, and follow the medical advice for further treatment or therapy.