Some dreams can cause panic and a sense of extreme unease, such as being chased, falling from a height, getting lost and making a fool of yourself in public, etc. These are called nightmares. Long-term nightmares not only affect the quality of sleep, but also affect physical and psychological health. Dreams can be divided into physiological dreams and pathological dreams. Physiological dreams usually do not affect work and study during the day. Pathological dreams can affect the mental state of the next day. Nightmares are pathological dreams, which are a kind of sleep disorder with horrible contents and cause anxiety and fear after waking up. Dreams are a special manifestation of intrinsic mental activity in the human body. High work pressure and thinking about problems will lead to long-term psychological depression, as will certain people who have experienced major trauma and changes; some factors will directly affect the sleep situation, such as room temperature, poor sleep environment, wrong sleep posture, too thick covers in winter, etc., causing physical discomfort; also, for example, exposure to too many stimulating things during the day will also cause abnormal brain Excitement can also cause nightmares at night. The frequency of nightmares has a certain relationship with gender. Women have more nightmares than men, because women feel more strongly about nightmares, and women are more likely to bring anxiety to sleep; for example, children are more likely to have nightmares than adults, because the brain is not fully developed, and emotions are easily influenced by the outside world. In addition, nightmares are also related to the personality of people, introverted, sensitive, mood swings are often attacked by nightmares. Therefore, there are many reasons for frequent nightmares, must be open to it, if after adjustment still can not improve, you can also carry out a physical examination to exclude physical disease.