There are several causes of bad breath. Usually it can just be a little bit of time since the last time you brushed your teeth, or you could be just waking up in the morning. But many times it's an indicator that there's some infection going on -- there's a gum problem in your mouth. Or you're not cleaning your teeth well -- you're not brushing and flossing really well, food is getting trapped and it's an indicator that things that are not good are happening in your mouth. Bacteria is multiplying in your mouth and it's starting to smell.
It also means your teeth are starting to decay and your gums could also be receding, which are really bad indicators. So if it's not just caused by something you ate -- which is occasionally what can happen, if you ate garlic or onions or some other food that doesn't really agree with you. If you have consistent or chronic bad breath, it usually means that there's something going on with your gums and in your mouth and in the way you're cleaning your teeth.
See a dentist. A dentist can really help -- and it's important to see what's going on in your mouth and have a dentist treat that so you can keep your teeth.
