Sinus infections or post-nasal drip (mucus running from your sinuses back into your throat) are responsible for up to 10% of cases of bad breath. There are a number of ways to combat it:  See your doctor. You may need an antibiotic to cure a sinus infection.  Use over-the-counter medication to dry up your sinuses and prevent mucus buildup. Try a saline spray to thin mucus and make it easier to expel. Try a sinus irrigator to rinse out your sinuses. Some medications will dry out your mouth, causing bad breath, while others contain chemicals that lead directly to bad breath. In particular, watch for the following medications:  Betel. Chloral hydrate. Nitrites and nitrates. Dimethyl sulfoxide. Disulfiram. Some chemotherapy medicines. Phenothiazines. Amphetamines. Smoking can leave your mouth smelling like an ashtray. The only permanent solution is to stop smoking, but you can also use mints or other breath fresheners to cover the smell.
تفقد جيوب الأنفية. عليك أن تعرف أن بعض الأدوية تسبب الرائحة الكريهة. أقلع عن التدخين لعلاج الرائحة الكريهة.