Dry mouth, bitter breath and bad breath can be caused by environmental factors or personal bad habits, but also oral diseases (such as dental calculus, periodontitis, etc.) and digestive diseases (such as indigestion, gastroesophageal reflux, etc.) and other factors. According to the different causes of its treatment methods are different, specific as follows. 1. Non-pathological factors: If you are in a dry environment for a long time, or you do not clean up the food residues in your mouth in time, you will experience dry mouth, bitter breath and bad breath. It is recommended to brush your teeth in the morning and evening, and place a humidifier in the room to moisten the air. 2. Oral diseases: such as dental calculus, periodontitis, can be ultrasonic cleaning, chlorhexidine gargle to improve the oral environment to relieve. 3. Digestive system diseases: such as dyspepsia can be taken under the guidance of the physician to promote gastrointestinal motility drugs (such as mosapride, domperidone). If gastroesophageal reflux can be under the guidance of the physician can be used to acid control drugs (such as omeprazole, ranitidine), and so on. In addition, the symptoms of dry mouth, bitter breath and bad breath can be improved by reducing meat consumption, eating more vegetables and fruits, and drinking more water. If symptoms persist, it is recommended to consult a specialist in the hospital to clarify the cause before treatment.