Dry and bitter mouth and bad breath in the morning consider poor oral hygiene, dry indoor air, digestive system diseases and other reasons. 1. Poor oral hygiene: too much plaque around the teeth, bacteria acid fermentation, coupled with a reduction in salivary secretion at night when you sleep, the loss of the cleaning effect of saliva, dry and bitter mouth in the morning, bad breath symptoms. 2. Dry indoor air: when you sleep at night, the indoor air is too dry, resulting in a heavy lack of water in the body, saliva secretion is reduced, and in the morning there is a dry and bitter mouth, bad breath symptoms. 3. Digestive system diseases: digestive dysfunction, chronic gastritis, reflux gastritis, acid fermentation in the intestinal tract causes the symptoms of dry and bitter mouth and bad breath in the morning. Dry and bitter mouth in the morning, bad breath, it is recommended that timely medical examination, under the guidance of the doctor for treatment and treatment.