What causes bad breath and how do I fix it?

Around 85% originates in the mouth — bacterial coating on the tongue, gum disease, dental decay, and dry mouth. Brushing, flossing, tongue cleaning, hydration, and dental treatment address most cases. Persistent odour despite good hygiene warrants checking for sinus, reflux, or metabolic causes.

Tongue cleaning is the most commonly missed step — the posterior tongue holds the bacterial coating responsible for most odour.

If hygiene is genuinely good, look for gum disease, dental decay, dry mouth from medication or mouth breathing, tonsil stones, sinus infection or reflux.