The common causes of dry mouth after nap include the following: First, physiological reasons: 1, lunchtime consumption of salty food, and did not drink water, may feel dry mouth after nap; 2, nap environment is drier, higher temperatures or open the air conditioning, but no humidification, the air is drier, resulting in increased loss of moisture, there will also be a nap after the symptoms of dry mouth. Second, pathological causes: 1, such as sleep snoring, sleeping with the mouth open to breathe will lead to increased loss of water from the mouth, usually have a dry mouth feeling; 2, the more common diseases, such as diabetes mellitus and uremia, due to a variety of reasons leading to increased urination, the body will be lack of water, so there will be a dry mouth feeling. The dry mouth caused by the above two diseases is not limited to napping, but can occur throughout the day or night, and is usually combined with more urination. Therefore, if dry mouth occurs only occasionally after a nap, it is not recommended to be too nervous, but if it occurs every day, it is recommended to go to the hospital for further consultation.