Insomnia is the most common of the sleep disorders. Insomnia refers to the difficulty in falling asleep, easy to wake up and early awakening in the middle of sleep, low quality of sleep, significantly reduced sleep time, and in some serious cases, patients also stay up all night. Long-term insomnia can easily cause distraction, fatigue, and even headache, excessive dreaming, sweating, memory loss, and can also cause a series of clinical symptoms and induce some psychosomatic diseases. Causes (a) Environmental factors: noise or light interferes with sleep, high temperature or cold affects sleep, uncomfortable bedding such as too hard or too thick or too thin bedding can affect sleep, changing the sleep environment such as chronic hospitalization or staying in a hotel can also cause insomnia, and co-sleepers, especially those who snore loudly, also affect sleep. (B) physiological factors: high-speed travel across several time zones (jet lag reaction), as well as from the day shift to night shift work, because the internal biological clock has not yet adapted to the new circadian rhythm, so insomnia also occurs. (iii) Numerous psychosocial factors: Stress and various life events can cause insomnia. Anxiety over one’s own or a loved one’s illness, fear of surgery, death of a loved one, worrying about exams or accepting an important job are all common causes of temporary insomnia. (iv) Somatic diseases: Various painful diseases, diseases that cause long-term suffering, such as heart and lung diseases, arthritis, advanced cancer, nocturia, gastrointestinal diseases, renal failure, hyperthyroidism, Parkinson’s disease, etc. often cause insomnia. (v) Psychiatric diseases: depression, schizophrenia, Alzheimer’s disease, anxiety disorder, obsessive-compulsive disorder, borderline personality disorder, etc. are often accompanied by insomnia symptoms. (vi) drug factors: the most common drugs that cause insomnia are caffeine, theophylline and various stimulants, as well as alcohol and appetite suppressants, which are called rebound insomnia. (vii) Sleep concomitant disorders: such as nightmares and night terrors. (H) Primary sleep disorders: such as idiopathic insomnia, delayed or early sleep phase syndrome, sleep apnea syndrome. (ix) Pseudo-insomnia: Pseudo-insomnia is also known as sleep state misidentification, that is, to have slept mistaken for not slept, and some people think of fatigue as insomnia.