The reason for waking up at 4:00 a.m. is a sleep disorder, mainly considering the following aspects. 1, related to the patient’s bad habits, such as patients often stay up late or irregular rest leading to biological clock disorders, patients wake up at 4:00 a.m. can not sleep, if they feel sleepy and weak during the day is called early awakening. 2, patients wake up at 4:00 a.m. may also be caused by physical disease, generally seen in the duodenal bulb ulcer When the body is fasting for a long time, the gastric juice secreted is likely to cause irritation to the duodenal bulb. If there is an ulcer surface, it will cause the patient to wake up at 3-4 a.m. because of pain and it is difficult to go back to sleep. If the patient has stomach pain, he must consult a doctor in time to improve the colonoscopy and gastroscopy.