# Why can't we smell it when we have bad breath... **URL:** \ **Category:** Factual Questions\ **Created:** [May 6, 2004, 1:31am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752 "2004-05-06T01:31:43Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Plan\_B](https://avatars.discourse-cdn.com/v4/letter/p/3ec8ea/32.png) [@Plan\_B](https://boards.straightdope.com/u/Plan_B)\ **Post date:** [May 6, 2004, 1:31am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/1 "2004-05-06T01:31:43Z")
but other people can? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 6, 2004, 1:40am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/2 "2004-05-06T01:40:36Z")
The problem is, you can’t exhale through the mouth and inhale through the nose at the same time. 😉 If you want to smell what your breath is like, lick the back of your hand, and sniff it. This will give you a pretty good idea if you need to suck on a mint before your big date or not. ---
**Author:** ![START](https://avatars.discourse-cdn.com/v4/letter/s/2bfe46/32.png) [@START](https://boards.straightdope.com/u/START)\ **Post date:** [May 6, 2004, 2:07am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/3 "2004-05-06T02:07:11Z")
> [@Q.E.D.](#): > > The problem is, you can’t exhale through the mouth and inhale through the nose at the same time. 😉 > > If you want to smell what your breath is like, lick the back of your hand, and sniff it. This will give you a pretty good idea if you need to suck on a mint before your big date or not. Doesn’t blowing inot your hand work…maybe not but everybody does it. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [May 6, 2004, 2:14am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/4 "2004-05-06T02:14:18Z")
I don’t think either method is going to accurately reflect what your breath smells like to others. Your olfactory sense is so closely linked to your mouth that it would become desensitized to any resident odors. Like smelling a rose all day, pretty soon you can’t smell it anymore. ---
**Author:** ![Plan\_B](https://avatars.discourse-cdn.com/v4/letter/p/3ec8ea/32.png) [@Plan\_B](https://boards.straightdope.com/u/Plan_B)\ **Post date:** [May 6, 2004, 2:42am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/5 "2004-05-06T02:42:48Z")
> [@Fear Itself](#): > > I don’t think either method is going to accurately reflect what your breath smells like to others. Your olfactory sense is so closely linked to your mouth that it would become desensitized to any resident odors. Like smelling a rose all day, pretty soon you can’t smell it anymore. That makes sense. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [May 6, 2004, 3:11am UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/6 "2004-05-06T03:11:19Z")
> [@Q.E.D.](#): > > If you want to smell what your breath is like, lick the back of your hand, and sniff it. This will give you a pretty good idea if you need to suck on a mint before your big date or not. I’ve heard this one, too. However, I was told to wait 15 seconds and then sniff. ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [May 6, 2004, 1:35pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/7 "2004-05-06T13:35:21Z")
> [@Q.E.D.](#): > > If you want to smell what your breath is like, lick the back of your hand, and sniff it. It just tells me I have a smelly hand. I knew that already! ---
**Author:** ![Flander](https://avatars.discourse-cdn.com/v4/letter/f/8c91f0/32.png) [@Flander](https://boards.straightdope.com/u/Flander)\ **Post date:** [May 6, 2004, 5:26pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/8 "2004-05-06T17:26:10Z")
[Ralph Whigham] My hand tastes funny. Heeaaa. [/Ralph Whigham] ---
**Author:** ![Schnauzer](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@Schnauzer](https://boards.straightdope.com/u/Schnauzer)\ **Post date:** [May 6, 2004, 6:40pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/9 "2004-05-06T18:40:00Z")
If you have a not-too-nice taste in your mouth then it’s quite likely that your breath pongs too. ---
**Author:** ![Harmonix](https://avatars.discourse-cdn.com/v4/letter/h/3ec8ea/32.png) [@Harmonix](https://boards.straightdope.com/u/Harmonix)\ **Post date:** [May 6, 2004, 11:25pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/10 "2004-05-06T23:25:34Z")
I second the lick the back of your hand routine. I do it all the time. I don’t generally have bad breath, but i’m so paranoid about it I carry mints everywhere I go. ---
**Author:** ![Harmonix](https://avatars.discourse-cdn.com/v4/letter/h/3ec8ea/32.png) [@Harmonix](https://boards.straightdope.com/u/Harmonix)\ **Post date:** [May 6, 2004, 11:26pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/11 "2004-05-06T23:26:39Z")
and brush your friggen tongue people! that’ll get rid of the bacteria for the majority of the day. ---
**Author:** ![plnnr](https://avatars.discourse-cdn.com/v4/letter/p/7ea924/32.png) [@plnnr](https://boards.straightdope.com/u/plnnr)\ **Post date:** [May 7, 2004, 12:46pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/12 "2004-05-07T12:46:17Z")
> [@Q.E.D.](#): > > The problem is, you can’t exhale through the mouth and inhale through the nose at the same time. 😉 > > If you want to smell what your breath is like, lick the back of your hand, and sniff it. This will give you a pretty good idea if you need to suck on a mint before your big date or not. Some musicians certainly can breath out their mouth and inhale through their nose at the same time. It is called circular breathing. ---
**Author:** ![Fish\_Cheer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fish_cheer/32/17179_2.png) [@Fish\_Cheer](https://boards.straightdope.com/u/Fish_Cheer)\ **Post date:** [May 7, 2004, 3:23pm UTC](https://boards.straightdope.com/t/why-cant-we-smell-it-when-we-have-bad-breath/243752/13 "2004-05-07T15:23:46Z")
> [@plnnr](#): > > Some musicians certainly can breath out their mouth and inhale through their nose at the same time. It is called circular breathing. Yup. I didn’t believe this at first, so I did a quick search: > [@](#): > > Physiologically its not possible to breathe in and blow out simultaneously, but it is possible to maintain air pressure, without blowing, by using your mouth like the airbag of a bagpipe. With this (small) reservoir of air maintaining the drone, you can sniff a quick breath through your nose, thus topping up your lungs so that you can then continue blowing. This process of snatching short sniffs will, with lots of practice, allow you to play continuously. It’s not easy though, and may well be the trickiest part of learning to play. (from a [Didjeridu Tutorial](http://www.mills.edu/LIFE/CCM/DIDJERIDU/instruction/lesson_circular_breathing.html))