The causes of sleepiness include physiological and pathological causes. Physiological causes are mainly due to excessive stress, physical fatigue, inability to fall into a deep sleep, etc. The pathological causes are often due to various diseases, such as neurological diseases, various medical diseases and psychosomatic diseases. The pathological causes are often due to various diseases, such as neurological diseases, various medical diseases and psychosomatic diseases. Neurological diseases include episodic sleep disorder, obstructive sleep apnea syndrome, cerebral blood supply deficiency, massive cerebral infarction, cerebral hemorrhage, brain tumor, etc. The diagnosis can be confirmed by head CT or MRI and EEG. Various internal diseases can cause sleepiness, such as anemia, hypertension, diabetes, hyperlipidemia, high blood viscosity, hypoparathyroidism, cardiac insufficiency, liver and kidney dysfunction, respiratory failure, hypotension, shock, etc. There are also psychosomatic diseases, such as anxiety and depression, which can cause daily lack of energy and the desire to sleep.