Bad breath associated with a dry mouth is caused by the reduction of saliva. This reduced saliva flow impairs the natural cleansing mechanisms of the mouth. Dry mouth, also known as xerostomia, can contribute to unpleasant oral odor and cause discomfort in the mouth.
Dry mouth is not a disease itself. Instead, it is a common side effect of over 400 prescription and over-the-counter drugs. Although dry mouth commonly occurs in most people after a night’s sleep, dry mouth may also occur with the use of certain medications, from prolonged snoring or mouth breathing, or as a result of salivary-gland problems. Additional reasons for dry mouth include a lack of fluid in the body (dehydration), nutritional deficiencies, the presence of another medical condition or disease (such as in autoimmune disorders like Sjögren’s syndrome), or radiotherapy to the neck and head areas.
If you suffer from dry mouth, you need to pay greater attention to your teeth. When maintaining your daily oral-hygiene routine of brushing your teeth, tongue, and gums and flossing regularly, use an extra-soft toothbrush with fluoride toothpaste after every meal and before going to bed. Also, avoid using tobacco products and consuming alcohol or caffeine, as these substances contribute to dry mouth and can exacerbate odor by increasing odor-causing bacteria.
To prevent bad breath caused by chronic dry mouth, make sure you are drinking enough water each day. Six to eight glasses of water a day is the minimum recommended amount; this will help reduce oral odor by washing away food particles and bacteria. Using a humidifier in your bedroom and avoiding breathing through your mouth can also help improve natural saliva flow. If your medications are making you experience bad breath and dry mouth, ask your dentist to recommend an over-the-counter saliva substitute remedy or speak to your doctor about adjusting your medication.