There are many reasons for dry mouth in bed at night, mainly including dietary reasons, environmental reasons and disease reasons. 1. Eat a salty dinner, or go to bed before eating some food containing more salt, will lead to increased plasma osmotic pressure, thus causing dry mouth, generally in the right amount of water, the symptoms can be reduced. 2. If you have the habit of turning on the air conditioner when you sleep at night, it will lead to the loss of moisture in the air, thus causing the symptoms of dry mouth and tongue, generally turn off the air conditioner or use a humidifier can be relieved. 3. If you have the habit of snoring, you will keep your mouth open for a long time, which will lead to the loss of moisture in the oral cavity and make you feel dry mouth. 4. Patients with diabetes mellitus, not only high plasma osmolality, and urination, will lead to dehydration, and high blood sugar can stimulate the thirst center, the symptoms of dry mouth. In addition, patients with uremia also have the performance of sleeping with dry mouth. In addition to the above, there are other conditions that may lead to dry mouth at night, if the improvement of lifestyle habits, the symptoms did not improve, it is recommended to go to the hospital for examination, follow the doctor’s instructions in a timely manner for targeted treatment, so as not to delay the course of the disease.