How to simply know our mouth stinks?

The way I know my bad breath is by licking my wrist.

Lick the part outlined and then wait a while until it dries, after the licked part has dried, then bring it close to your nose and inhale, if it smells, you probably have bad breath. The condition is not to try this method right after brushing your teeth, because it must smell good, at least wait 1-3 hours after brushing your teeth.

The important thing is not to be long in smelling the aroma, you will faint.