I smoked for twenty years and recently quit, i have allergies and post nasal drip. no matter what i do i can not get rid of the post nasal drip and subsequent bad breath, quitting smoking has helped somewhat but not really, i use saline nasal spray and a

Sinus infection: The problem may be chronic sinusitis. Saline irrigation with a neil med sinurinse bottle might do a better job of clearing any debris. A good exam by an ent, including a nasal endoscopy would best examine for the origin of bad breath. Sometimes your breath isn't as bad as you imagine, also.

Bad breath: See your ENT for post nasal drip. Meanwhile use a tongue scraper to clean your tongue few times per day because the bacterial can sit and harbor on top of your tongue perpetuating the bad breath.

Mouth breathing: Odors causing bad breath come from the stomach, lungs or sinuses. Your bad breath is the result of clogged nasal passages. Post nasal drip is another symptom of your nasal-sinus disease. It may be a sinus infection, nasal polyps, or allergic or nonallergic rhinitis. When your nose is blocked you breathe through your mouth. Dry mouth and odor is the result. Restore nasal breathing & odor resolves.