Post nasal drip is a common cause of bad breath, even though it is not often talked about. People are more likely to blame halitosis on a build up of bad oral bacteria. Post nasal drip is also harder to get rid of than a bacterial buildup on the tongue.
Post nasal drip is a flow of mucus from the nasal area regularly leaking down into the throat area. This mucus feeds nutrients to the bad oral bacteria in the throat and the mouth, so the chances of having bad breath are much higher. This problem can be chronic and hard to treat in comparison to other ailments that cause bad breath.
Most bad breath-causing anaerobic bacteria lives on the dorsal (back) area of the tongue, so when mucus drips down from nasal passages, it is in easy access to the bacteria. Also, if you have never had your tonsils removed, debris can collect there, allowing bacteria to thrive even more.
You may need to see a doctor for this problem if it does not go away. To start off, you may brush after all meals and before going to bed. Use a tongue scraper and try to gargle twice a day. Having your tonsils removed may be an option, but it is not safe for everyone.