There are two main types of reasons for not being able to sleep when waking up in the second half of the night: 1. Occasionally, patients cannot sleep when waking up in the second half of the night because they sleep too much during the daytime leading to waking up very early in the second half of the night, and it is difficult to sleep after waking up. This type does not require medication, and the abnormal sleep rhythm can be corrected by adjusting work and rest habits and exercising properly. 2, physical diseases that cause waking up in the second half of the night and not being able to sleep, it is recommended that patients go to a regular hospital to improve blood sugar, blood pressure, blood lipids and night polysomnography, cranial CT or MRI, etc., to clarify the specific cause. If there are patients with abnormal blood sugar, blood lipids and blood pressure, it is recommended to strictly control blood pressure, blood sugar and blood lipids.