Bad Breath

[mad_for_it]

Why is it that people can smell other people's bad breath but the person with the bad breath can't smell it themselves when their nose is right there at the mouth? just wondering.........

[xyzzyplugh]

selective amnesia? attenuation? I once had to visit a maggot farm, the stench was unbelievable! When I asked a worker how he coped with the smell, he said 'What smell?'

[andy hughes]

This is logical conjecture rather than sound scientific knowledge - i imagine in our primeval days, when smell was a far more important sense than it is now - odour detectors were required to alert us to danger, food, friends, and so on, so a built-in immunity to our own odours left our sense of smell free for more important signals, and this has lasted through evolution. Some people must be similarly unable to detect their own body odour, which remains freely available to the rest of us!

[darth vader]

because in natural breath, or talking etc. your breath is directed out and away from your body and hardly ever gets near your nose, whereas someone talking to you is directing their breath towards you, and the breath will go towards your nose. Try jutting your lower jaw out as far as possible so that you can direct your breath upwards - you can breathe in through your nose at the same time as breathing out through your mouth with a bit of practice (you don't actually breathe out - instead expel a mouthful of air) and hence smell your own breath! warning - don't try this after eating garlic bread :-)

[JohnPPotts]

Presumably you'll become habituated to how your breath smells, in the same way that if you sit in a room full of sweaty people (well, Ok, men) you'll only really notice how rank it smells if you leave and then return.

[mikewith]

Another example of the phenomenon JohnPPotts describes is the rank bad smells that build up, imperceptibly, during a long-haul plane flight. Apparantly the *worst* job in the world is being the person who opens the doors from the outside at the end of such flights, to be met by several hours' worth of collected BO, farts, dodgy food and smelly feet. But the people *inside* the plane can't smell it at all!