Waking up at 3-5 o’clock in the middle of the night with a dry and bitter mouth may be caused by physiological factors such as indoor stuffy heat; it may also be caused by diseases such as mouth ulcers and dry syndrome. Depending on the cause of the disease, you can follow the doctor’s instructions to choose the appropriate way of treatment, such as general treatment, medication and so on. 1. Physiological factors: If you wake up with a dry mouth at 3 to 5 o’clock in the middle of the night due to stuffy indoor heat, a dry environment, or sleeping with your mouth open to breathe, it is recommended that you keep the room ventilated and breathable, with the right temperature and humidity, and drink plenty of fluids to improve the symptoms of a dry mouth and bitterness. 2. Mouth ulcers: If you have mouth ulcers that cause you to wake up at 3 to 5 in the middle of the night with a dry mouth and a bitter taste in your mouth, you can use watermelon cream, mouth ulcers and other medications to spray on the affected area to promote the healing of the ulcers. Usually should keep the mouth clean, avoid eating spicy and stimulating food. 3. Dry syndrome: If the dry syndrome leads to dry mouth and bitterness in the middle of the night 3 to 5 o’clock, the patient can use artificial saliva to relieve the symptoms of dry mouth and bitterness; can also be oral hairy fruit rue alkaloids, cevimeline and other acetylcholine analogs, stimulate the function of the salivary glands. If you wake up in the middle of the night 3 to 5 o’clock dry mouth, exclude physiological factors, it is recommended that the patient to the hospital, a clear cause of the cause of treatment in accordance with the doctor’s instructions, the drugs should be used in accordance with the doctor’s instructions.