Drowsiness and insufficient sleep are generally manifestations of cerebral ischemia and hypoxia, and the common causes are as follows: 1. Low sleep quality: drowsiness and insufficient sleep may be caused by low sleep quality at night, such as the presence of patients with excessive dreaming and early waking, which can easily lead to poor sleep quality, resulting in drowsiness and mental fatigue during the day. 2. Combined serious diseases: if patients have serious diseases, they can also The phenomenon of drowsiness, such as epilepsy, cerebrovascular disease, dementia, pulmonary encephalopathy, liver and kidney insufficiency, heart failure, severe diabetes, severe hypertension, neurasthenia, etc., these conditions may lead to drowsiness, mental fatigue and other phenomena. Therefore, when drowsiness and lack of sleep occur, the cause needs to be clarified through relevant examinations, including polysomnography, cranial MRI, blood glucose measurement, blood pressure measurement, blood routine, liver and kidney function tests, cardiac ultrasound, electrocardiogram, etc., and then give symptomatic treatment after clear diagnosis.