Chronic bitter mouth is related to oral diseases, gastrointestinal diseases, and liver and gallbladder diseases. Oral diseases including gingivitis, periodontitis, and apical inflammation have the potential to trigger bitter mouth. Patients with burning mouth syndrome may have altered taste sensations and some may have bitter mouth. Bitter mouth can also be triggered by the irritation of taste buds due to oral bacteria growth. Gastrointestinal disorders that make food difficult to digest and build up in the gastrointestinal tract triggering indigestion can also cause bitter mouth symptoms. Bitter mouth often occurs with liver diseases such as hepatitis, or cholecystitis when bile flows backward into the stomach and mouth. In addition, frequent late nights, irregular work schedules or eating greasy food can also lead to bitter mouth. All, bitter mouth first to the stomatology department to rule out oral diseases, further examination needs to go to the gastroenterology department, long-term recommendations for early medical treatment.