How to smell your own breath as a self-test for halitosis (bad breath).

- Having breath odor is bad enough but not knowing that you do is even worse.  6 ways to self-test for odors - This page outlines 6 methods you can use to objectively smell your own breath, and then judge how offensive it really is.

How to tell if you have bad breath. - Self-testing

The challenge - Why evaluating the odor of your own breath can be difficult.
Illustration showing the connection between the mouth and nose.

Odors from your mouth escape to your nose, thus desensitizing its ability to detect them.

While knowing if we have mouth odor is something that's important to all of us, the way our bodies are set up makes it difficult to smell, and then judge, the quality of our own breath. Here's why:

  • Our mouth is connected to our nasal cavity by way of an opening that lies behind the soft palate. And this connection serves as a direct passageway for any smells that originate in the mouth.
  • But due to a process termed "adaptation," our sense of smell becomes accustomed to any odors that persist. So after a while, we simply don't notice them any longer.

  • That means it's quite possible, and even likely, that a person who has halitosis simply doesn't know it, because they can literally no longer smell their own odor.

So with self-testing, the objective is to figure out a way around this conundrum.

How to accurately smell and judge your own breath odor.

The solution that's needed for self-testing is to devise a way where you can evaluate your breath indirectly.

You need to transfer its odor to another object, and then smell it. Here are some ways that you can do that:

Image showing the anterior part of the tongue.

The tip of the tongue is fairly self-cleansing.

Test #1 - The wrist test.

  • With this evaluation, you first lick your wrist with your tongue.
  • Wait about five to 10 seconds, so to let the saliva dry a little.
  • And then smell it from a distance of about an inch or so.
Did you pass this first test?

What did you find out? Did you find the smell very objectionable?


While this method of testing is a reflection of the way that your mouth smells, more precisely it's just an evaluation of the odor associated with the tip end of your tongue. (Its "anterior" portion, the part that extends out of your mouth when you lick something.)

And that's the catch with this test. It may not be totally accurate in what it reports because the anterior portion of the tongue is relatively self-cleansing. And as a result, it may under report cases of halitosis.

Image showing the he posterior part of the tongue.

The back part of the tongue usually harbors debris that is the primary cause of bad breath.

Test #2 - The spoon test.

Now, try this second experiment. It will check the odor coming from the back portion of your tongue (its "posterior" region).

This part of the tongue isn't as self-cleansing. And it's usually the region of the mouth from which a person's breath odors really originate.

  • Select a small spoon from your silverware drawer.
  • Turn it upside down, place it at the very back of your tongue and then draw it forward.
  • Be deliberate but gentle. (Don't be surprised if this test triggers your gag reflex a little bit.)

Image of spoon full of bacterial debris scraped off a person's tongue.

Smelly debris scraped off the back part of a person's tongue.


Take a look at the gunk you've scraped off. It can be that it's just a clear runny liquid. But often enough, instead it's a thick whitish, yellow or even brown goo.

Generally speaking, the darker the color and thicker the goo, the more likely you're going to discover breath odor.


Now, go ahead and take a whiff. What do you think? Not so bad, or pretty nasty?

The baggie test - If you want to amplify the smell of the scrapings, close them up in a baggie and then put it somewhere warm (around body temperature is good).

For example, you might shine the high-intensity lamp on your desk on it. Then after 10 or 15 minutes, open the bag and take a whiff.

So now you know, that's what you smell like to others.

It's this odor, as opposed to the sampling from the anterior portion of your tongue in test #1, that's probably the way your breath smells to other people.

And if you haven't been cleaning the back portion of your tongue, it's probably pretty foul.

By the way, now you also know why you have bad breath.

It just so happens that this second test reveals why most people have breath odor. The most common underlying cause of halitosis is the whitish coating that covers the surface of the posterior portion of a person's tongue.

Other ways to smell and self-check your breath.

Here are some additional testing methods you can use to evaluate the quality of your breath. Just like with the methods above, the goal is to take a specimen from your mouth, that can then be reintroduced to your nose as a (fresh, new) independent sample.

a) The gauze test.

Here's a variation on the way you can run the spoon test described above. It's not better, just different. Dentist's sometimes use this method in their office.

  • Get a 2 by 2 inch square of medical gauze, the kind used for bandages.

    [You should be able to find it at any pharmacy. Get just normal gauze (it looks and feels like very loosely woven cloth), not the ouch-less, non-stick variety. Anything larger than 2 by 2 inches is fine too, just cut it down so it fits in your mouth.]

  • Stick your tongue out and look for any coating on it. Expect it to be on the furthest back portion.
  • Take the gauze, and starting from the rear and working forward, wipe the surface of your tongue where the build up is heaviest a couple of times.
Inspect the gauze.

Once you're done, take a look at, and smell, the gunk you've wiped off.

  • It likely has a yellow to brown color.
  • When you smell it, it probably won't be all that pleasant.

    [If you're having trouble getting a whiff, you can amplify the odor by using the baggie trick described above.]

Whatever the results (good or bad), that's pretty much how your breath smells to others.

b) The airbag test.

An obvious way of self-testing is to simply exhale into an odorless plastic bag, and then smelling what's there. This method is sometimes used in scientific studies.

  • In practice, one difficulty involved is finding a truly odorless bag. A gallon-sized food storage bag is an option.
  • Another obstacle is that with each of the above tests, some of the debris from which the malodor emanates is included in the sample, thus helping to perpetuate its smell.

    And as described in our baggie test above, allowing this kind of sample to incubate at body temperature for some minutes can help to accentuate its odor so it is more easily identified.

    In comparison, samples of expired breath have been shown to contain very few microorganisms. So a bag containing just the gases may be more difficult to evaluate.

Section references - Winkel


c) The floss test.

This evaluation is different from the other self-testing methods outlined on this page. And as such it can be a very valuable source of information.

It tests for bad breath whose point of origin is from between your teeth. (FYI: This is the second most likely source of bad breath. And an especially common one with older individuals.)

How to perform the test.
  • Dispense a new piece of dental floss for flossing your teeth.
  • A length of unwaxed floss generally makes the best choice. It's loose individual strands will be the most effective in trapping debris.

    As an alternative, other types of floss can work. Although, due to their solid, one-piece nature (this includes stranded waxed floss), they'll tend to trap less debris.

    Also, whatever type of floss you do choose, make sure it is an unflavored kind.

  • Use the floss to floss your teeth. Between your back teeth will probably tend to be the most fertile ground for detecting breath odors.

    The flossing technique you use is important. (The emphasis here is to floss subgingivally, which means to let the floss slide below the gum line as you clean.)

  • Remove the floss and smell it from a distance of about an inch. (Especially make sure to smell any section that still retains a glob of debris.)

Section references - (Sources for all of the self-testing methods described above.) - Aydin, Schumacher, Aylikci, Winkel

A tried and true way to tell if you have bad breath.

Get someone else's opinion.

Another way to check your breath is an obvious one. Just ask someone else what they think.

Actually, this makes a very good plan and is generally regarded as a reliable way to confirm a chronic breath problem. That's because, as we described above, the human nose tends to ignore persistent odors, and even when doing testing like we describe above, it's still sometimes hard for us to smell ourselves.

Another good reason.

Beyond just not being able to detect our own malodor, there's another reason why getting an opinion from someone else can be important.

There's a classification of bad breath termed pseudo-halitosis where the person suffering from it is under the impression that they have a breath problem but really don't. Or at least not to the extent they think they do.

So in cases such as these, asking someone else what they think can be very valuable in helping to lay to rest mistaken impressions and fears.

Who makes a good person to ask?

  • Obviously, if you have a significant other, they make a good candidate.
  • You might ask your dentist or hygienist at your next appointment. After all, evaluating the status of your oral health is their job.
  • If that's too personal for you, try asking a kid. Sometimes the least inhibited and most honest answers come from young children.

Our next page discusses the odors associated with bad breath and where they come from. After all, until you know where your halitosis originates, you won't be able to cure it.

If instead you're interested in learning about the scientific side of evaluating halitosis, we have pages that explain: