For fresh breath

You Take a Prescription Drug

Check your medicine cabinet—it could be the source of your not-so-fresh breath.

Hundreds of prescription and over-the-counter drugs—for everything from allergies to high blood pressureto depression—can cause dry mouth, one of the most common triggers of bad breath. They may block the action of acetylcholine, a brain chemical that tells nerves to switch on the salivary glands.

Fix it: Ask your doctor to adjust your dosage or suggest an alternative medication that doesn't list dry mouth as a side effect. In the meantime, frequently sip water to stimulate the production of saliva, which keeps the mouth moist and clean. Limit coffee consumption and try to breathe through your nose, not your mouth, to avoid drying it out further. OTC saliva substitutes can also help keep your mouth moist, according to the Mayo Clinic. Look for ones containing carboxymethylcellulose or hydroxyethylcellulose to help thicken saliva.