Take a piece of white, unflavored dental floss (thick) and use it between 4 upper and 4 lower back teeth. Move the floss around for a few seconds in each place, then look at it. Is it discolored? Wait a moment. Smell the floss. Is there an odor?

Still not sure? Try this. Take a piece of clean gauze, it's available at any drugstore. Stick your tongue out and, firmly, wipe the furthermost back portion of your tongue two or three times. Wait a moment, then smell the gauze. Is there an odor?

If either of these tests is positive, it's a good bet you have halitosis.

It's important when doing either of these tests to wait a moment before smelling the floss or gauze. Why? The same reason that we have a hard time detecting our own bad breath.

It's called adaptation, a sensory phenomenon peculiar to taste and smell. Have you ever entered a room with a particularly bad odor? After you stay in the room awhile the odor seems to get better. In reality the odor is still there, but you have adapted to it: lost your awareness of it. So it is with our own halitosis. It's also why people in close proximity to us, and even our loved ones, may at first smell our bad breath, but then seem not to notice it as their own protective adaptation comes into play.