If you have a bitterness of the taste inside the mouth, there are many reasons. It may be related to problems in the mouth such as gum disease, mouth infections or dry mouth caused by lack of drinking water.
This may be due to lack of Oral care, whether the tongue or gums and teeth, and lack of dental brushing, the accumulation of bacteria, causing bad breath & bitterness of taste.
One of the most important reasons for the bitterness also (smoking), which is a bad health habits that negatively affect the taste and smell of the mouth. As well as some other causes such as the incidence of some diseases, medications or hormone imbalance.
Therefore, once you feel a bit of bitterness or different taste you should visit the doctor to know the reasons and treatments.