A fat stomach may be caused by physiological factors such as obesity and heredity, or it may be caused by diseases such as polycystic ovary syndrome and Cushing’s syndrome. 1. Physiological factors: excessive obesity, heredity, alcoholism, may lead to excessive accumulation of local fat, fat stomach. If there are no accompanying physical symptoms, it is a normal phenomenon and there is no need to worry too much. 2. Polycystic Ovary Syndrome (PCOS): The cause of PCOS is not yet clear, and may be due to a combination of genetic and environmental factors. Patients may have hairiness, acne, obesity and other symptoms, may be abdominal obesity type, manifested as fat stomach. 3. Cushing’s syndrome: the cause of Cushing’s syndrome hypothalamus-pituitary-adrenal axis dysregulation. Patients can appear centripetal obesity, and accompanied by hypertension, muscle atrophy, acne, impotence, scanty menstruation, loss of libido and other symptoms, and some patients can appear fat belly. There are many reasons that lead to fat stomach, it is recommended that patients identify the cause of the disease in time and take relevant treatment measures, so as not to delay the condition.