1. What is normal sleep? Normal sleep averages 6-9 hours per night, and these 6-9 hours are divided into 4-6 sleep cycles, with each cycle lasting an average of 90 minutes, and consisting of four phases of rapid eye movement (REM) sleep and non-REM sleep occurring sequentially, of which phases 1 and 2 of the four phases are the process of light sleep, and phases 3 and 4 represent the state of deep sleep. When the sleeper is awakened at any point in the course of the sleep cycle and resumes sleep, he does not return to the sleep phase that awakened him, but starts from the initial phase. Therefore, quality sleep in addition to ensuring sufficient time, but also to ensure a high degree of quality. 2, the role of sleep Adequate sleep for the maintenance of physical health, to maintain a happy mood, improve the efficiency of work and study has an obvious and important role. Each period has a different role, a feature of rapid eye movement sleep is dreaming, dreaming can reduce and relieve mental stress and promote the recovery of energy. During non-fast eye movement sleep 4, the brain secretes a large amount of growth hormone, which is very important for the growth of cartilage tissue and muscle tissue. It promotes protein synthesis, reduces protein breakdown, and new synaptic connections are established, which facilitates the maturation of the young child’s nervous system, promotes learning and memory activities, and the recovery of energy. It can also accelerate the healing of damaged tissues and has the function of promoting the recovery of physical strength and energy. 3, the performance of non-organic sleep disorders non-organic sleep disorders are divided into the following categories: non-organic insomnia (shortened total sleep time, difficulty in falling asleep, shallow sleep, easy to wake up, early waking up, dreaming); non-organic narcolepsy (uncontrollable sleepiness for a short period of time); non-organic sleep-wake rhythm disorders; sleepwalking (nocturnal wanderer); sleep terrors (nocturnal terrors); nightmares (nightmares) and so on. 4, the harm of non-organic sleep disorders (1) can lead to physical discomfort: poor daytime energy, poor concentration, dizziness, headache, bad mood, poor appetite, memory loss, etc.. (2) It can lead to somatic diseases: such as fall, coronary heart disease, hypertension, cardiovascular disease, asthma, peptic ulcer, dementia and so on. (3) It can lead to psychological diseases or even serious mental diseases: depression, anxiety, neurosis, bipolar disorder, schizophrenia, etc.; (4) Aggravation of pre-existing diseases: such as brain tumors, post-stroke syndrome, restless legs syndrome, mental diseases, etc.; 5. How to prevent non-organic sleep disorders? (1) Sleep regularly, maintain a relaxed state of falling asleep, go to bed and get up at a fixed time every day, and do not sleep during the day; (2) the darker the bedroom, the better, the temperature is suitable, do not watch TV while sleeping, do not put an alarm clock; (3) within 4 hours before going to bed, do not do strenuous exercise, do not do stimulating activities before going to bed that are easy to cause excitement, do not watch tense movies and TV dramas and novels, do not have a full stomach before going to bed, and avoid smoking, alcohol, tea and coffee and other stimulants; (4) how to prevent non-organic sleep disorders? (4) dinner should not be too full, 2 hours before bedtime without eating indigestible food; (5) sleeping pills can cause a compensatory increase in heterophasic sleep, resulting in frequent nightmares, so do not take sedative-hypnotic drugs. (6) If the quality of sleep is poor for more than 3 days per week and 4 weeks in a row, you should go to the regular hospital to see the insomnia department.