What causes bad breath?
Most bad breath is caused by bacteria in the mouth breaking down food particles and releasing smelly sulfur compounds, especially on the back of the tongue and between teeth.
Bad breath, or halitosis, often comes from poor oral hygiene. If teeth, gums and the tongue are not cleaned regularly, food particles remain and bacteria multiply. Gum disease and tooth decay can also cause persistent odors. A dry mouth makes it worse, because saliva helps wash away bacteria.
Morning breath happens because saliva production drops during sleep. Strong foods like garlic and onions release compounds that are absorbed into the blood and breathed out through the lungs. Smoking, some medicines, dieting and infections in the nose, throat or sinuses can also cause bad breath.
Preventing it
Brushing twice a day, flossing, cleaning the tongue, drinking water and visiting a dentist regularly can prevent most bad breath. Sugar-free gum helps by increasing saliva. Persistent bad breath despite good hygiene can sometimes signal another health condition and is worth checking with a dentist or doctor.
Did You Know?
Many people cannot judge their own breath accurately, because the nose gets used to familiar smells.
This answer is general information, not medical advice. For a personal health question, talk to a doctor.