Wake up at three or four o’clock in the life of this situation, common in sleep apnea syndrome, depression, neurasthenia and other conditions. If such a situation occurs for a long time, you should consult a doctor in time to find out the cause of the disease. 1. Sleep apnea syndrome: the main manifestation of this disease is snoring, drowsiness, and because of the repeated collapse of the trachea obstruction leads to a decrease in blood oxygen concentration, which in turn triggers the body hypoxia, the body will be forced to wake up. 2. Depression: this actually belongs to the sleep disorder of early awakening symptoms, but also accompanied by depressed mood, loss of pleasure, loss of interest and other symptoms, signs of depression, long time will affect the sleep. 3. Neurasthenia: If the prolonged stress is too great, and often stay up late, often in a high-pressure environment will often cause neurasthenia, and waking up after it is difficult to fall asleep again. Patients who have such a situation for a long time, it is recommended to go to the hospital to find out the cause of the disease so as not to delay the condition.