Here are some factors that may lead to bad breath:

1.

Chronic bad breath usually has an underlying medical cause such as throat, nose or lung infections and sinusitis, bronchitis, gastro-intestinal conditions or diabetes.

2.

Poor dental hygiene. Without regular brushing and flossing, bacteria and bits of food can get trapped in between your teeth, which release an unpleasant odour after some time.

3.

Smoking.

3.

Consuming strong, odorous foods like garlic, onions and coffee. If you are aware that your breath is not as fresh as you would like it to.