Sleeplessness in the second half of the night is a typical symptom of insomnia, including difficulty in falling asleep, short sleep duration, and easy to wake up early. There are many reasons for this, including environmental factors such as noisy sleep environment, strong indoor light, and unsuitable room temperature, all of which can cause insomnia and lead to sleepless nights. First of all, physiological factors such as age, as age increases sleep time will be correspondingly shortened, resulting in easy to wake up early or sleep difficulties. Secondly, drug factors can also affect sleep, such as aminophylline, caffeine and glucocorticoids, all of which can excite the brain nerves and cause sleeplessness at night. Finally, disease factors such as frequent urination at night, coughing, itchy skin and painful irritation can affect the quality of sleep and cause insomnia. To sum up, there are many causes of insomnia, which need to be dealt with according to the specific causes.