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Along with a stuffy nose, fever and headache, colds can also produce an unpleasant breath. When it comes to a sinus infection, bad breath is often one of the first side effects as the sinuses drain into the back of your throat. Luckily, sinus infections are treatable, and when the infection is over, halitosis can usually go away.

Sinus Infections

Sinus infections occur when thick mucus or physical structures prevent the sinuses from draining properly, as explained by the National Institutes of Health (NIH). Consisting of air-filled structures behind the cheeks, eyes, forehead and nose, the sinuses usually contain no bacteria or other infectious agents. As air flows through them, thin mucus travels through the small hairs in your nasal cavity and drains into the back of the throat.

But when colds and allergies create excess mucus or nasal polyps, nasal bone spurs and similar structures prevent this mucus from draining – allowing bacteria, viruses and fungi to thrive. Certain medical conditions that prevent the small hairs in the sinuses from working well can also lead to infections in this way.

How They Create Bad Breath

Colds create bad breath by drying out the mouth as you breathe through it when your nose clogs up. The mucus in infected sinuses, however, smells bad on its own, and the air you breathe out comes into contact with it. Infected mucus drips out of the sinuses and down the back of the throat, where it meets the air you exhale and the odour from the infection can transfer to your breath.

You can help improve the smell of your breath by brushing twice a day with a fluoride toothpaste. As important as this habit is, though, this is a short-term fix; your bad breath won’t go away until the sinus infection clears up.

If symptoms don’t improve, or if you experience a headache, a fever over 102.2 F or severe swelling around the eyes, visit your physician. They can prescribe antibiotics for a bacterial infection or another appropriate medication given the source of the problem.

Preventing Sinus Infections

If you regularly experience sinus infections, ask your physician about more systemic tests for finding the cause. An ear, nose and throat specialist can examine your sinuses with a fiberoptic scope, or order MRI or CT scans to see if the structure of your sinuses is slowing the travel of mucous.

When a dental checkup is considered all clear but you still have bad breath, a sinus infection may be the cause. By working quickly to treat your sinus infection, bad breath can turn fresh again so you can ride out the condition with as few side effects as possible.