HOW TO TELL IF YOU HAVE BAD BREATH...

Bad breath can be embarrassing. It's easy to unwittingly walk around with a mouth full of halitosis until a brave friend–or, worse, a crush or romantic partner–tells you that your breath smells bad. Fortunately, there are several "breath tests" that you can perform on yourself to discern what your breath smells like. These methods may not tell you exactly what other people smell, but they should give you a good indication.

Smelling Your Saliva

LICK THE INSIDE OF YOUR WRIST


Lick the inside of your wrist. Wait 5-10 seconds for the saliva to dry. Try to do this discreetly–when you're alone–and not in a public place, or you may get strange looks from those around you. Avoid trying this test just after you've brushed your teeth, used mouthwash, or eaten something minty, as a freshly-cleaned mouth may give you inaccurate results.

SMELL THE INSIDE OF YOUR WRIST WHERE THE SALIVA


Smell the inside of your wrist where the saliva has dried. This is, more or less, what your breath smells like. If it smells unsavory, then you may need to improve your dental hygiene. If it doesn't smell like anything, then your breath probably isn't too badbut you might need to try another self-test to be sure.
Bear in mind that this method primarily pulls saliva from the tip (anterior portion) of your tongue, which is fairly self-cleansing. Thus, smelling your licked wrist will only tell you how the best-smelling part of your tongue smellsand most bad breath tends to originate from the back of the mouth where it meets the throat. [1]
You can wash the saliva off of your wrist, but don't worry if you don't have access to water or sanitizer since the smell will dissipate quickly as the skin dries.
If your breath problems are relatively minor, you may not be able to smell much. If you're still worried, consider trying another self-testing method to give yourself a "second opinion".

TRY SWABBING THE BACK OF YOUR TONGUE


Try swabbing the back of your tongue. Use a finger or a piece of cotton gauze to reach deep into your mouth–but not so far back as to trigger your gag reflex–and wipe the surface of your tongue at the back of your mouth. Any bad-breath bacteria lurking back there will come off onto the swabbing tool. Sniff the swab (your finger or the cotton) for an accurate sense of how the back of your mouth smells.
This method may reveal bad breath more precisely than merely licking your arm. Chronic halitosis is caused by bacteria that breed on your tongue and between your teeth – and most of these bacteria congregate near the back of your mouth. The tip of your tongue is fairly self-cleaning, and you may clean the front of your mouth more regularly than the back of your mouth. [2]
Try swishing with antibacterial mouthwash–in the front and the back of your mouth–to keep bacteria from hiding out on the back of your tongue. Gargle with mouthwash, if you can, to keep bad-breath bacteria from congregating in your throat opening. When you brush your teeth, make sure to brush your furthest back teeth, and be sure to brush your tongue and gums.

It's really good to take note of your health especially your mouth.