Narcolepsy can occur at all ages, and the initial symptom is usually a feeling of very heavy drowsiness during the day. The causes of narcolepsy are multiple, such as sleep deprivation at night, malnutrition, obesity, depression, cerebrovascular disease, diabetes mellitus and many other etiologies. Long-term staying up late leads to insufficient sleep time, poor sleep quality, or poor respiratory tract leading to nocturnal respiratory sleep apnea, which disrupts the biological clock over time. This in turn leads to fatigue, drowsiness, dizziness, mental confusion and other signs of neurological weakness. Adolescents in the process of growing body if the nutrition supply is not enough also easy to lead to sleepy love sleep. Obesity and overweight people can also cause excessive daytime sleepiness due to the overload of the whole body. People with depression are three times more likely to feel sleepy during the day than normal people. Diseases of the cerebrovascular system also often cause drowsiness. Diabetes mellitus is twice as likely to cause drowsiness as normal. Patients with thyroid gland often show narcolepsy due to low basal metabolism. Current sleep institute tests have again verified multiple causes of narcolepsy, such as sleep deprivation, sleep apnea, and mood disorders. In conclusion, the causes of drowsiness are multifaceted. Therefore, it is necessary to start from various aspects such as proper diet, sleep protection, emotional adjustment and disease prevention to relieve narcolepsy.