Around 90 percent of bad breath starts in the mouth, from bacteria on the tongue, trapped food between teeth, or gum disease. Mouthwash alone only masks it; the odour returns within the hour.
The lasting fix is mechanical: brush, floss, gently clean your tongue, and stay hydrated. If fresh breath still eludes you after good hygiene, a dental visit can rule out gum infection, a hidden cavity, or dry mouth.