There are many reasons for old dreams, many people often dream at night when they sleep, and sometimes even woke up by dreams, this situation is mainly caused by the following aspects: first, mental stress leads to dreamy, long time mental stress, long stay up late and other problems can lead to difficulty in falling asleep, early awakening, dreamy, excessive mental stress for a person’s normal life, sleep pattern is very big. Second, the poor sleep environment leads to dreamy situation, sleep environment is excessively noisy, often with sound, light stimulation will make the quality of sleep decreased, shallow sleep time prolonged and cause dreamy, and even have nightmare problems. Third, physical diseases lead to dreamy, such as heart disease, prostate enlargement and other problems are likely to cause sleep at night, waking up, repeatedly fall asleep will easily cause light sleep, dreamy situation, and even dream constantly.