Dreams can occur at any time of sleep and are coexistent with humans. There are many different kinds of dreams, and dreams that cause a person to feel frightened and extremely upset, such as being chased, falling from a height, getting lost and making a fool of oneself in public, are called nightmares. Occasional nightmares have no real significance, but there are often a number of reasons for frequent nightmares. Somatic factors: If you dream for a long time about clinical manifestations of diseases related to a certain area, you may have a problem with the health condition of that area, but it is not certain and further examination is needed. External environmental factors: such as uncomfortable room temperature, light stimulation, wrong sleep posture, too thick covers in winter, etc. causing physical discomfort; exposure to too many stimulating things during the day causing abnormal brain excitement, such as watching horror movies, all these factors will directly affect sleep; psychological factors: dreams are a special manifestation of intrinsic mental activity in the human body, high work pressure, thinking about problems will lead to long-term psychological depression, in Physiological factors: women are more likely to bring anxiety to sleep, so women feel more strongly about nightmares, women have more nightmares than men; in addition, because the brain is not fully developed, emotions are susceptible to external influences, children are more likely to have nightmares than adults; in summary, beautiful dreams do not always come true, nightmares are even more so, so we should treat them with a positive and optimistic attitude. Adjust your mind and ensure good sleep.