What Causes Bad Breath

Bad breath, medically referred to as halitosis,  is an embarrassing and sometimes worrisome oral health condition. It may be caused by poor dental habits, the food and drinks we consume, oral infections, and underlying health conditions.  

Everyone gets to experience unpleasant-smelling breath one time or another.  Sometimes it’s temporary, but sometimes it’s persistent.  What really causes bad breath?  For sure it’s more than just not brushing your teeth.  Let’s take a look at what causes bad breath and what you do about them.  

What causes bad breath

Bacteria caused by poor dental habits

If you don’t regularly and properly brush your teeth, floss them, or rinse your mouth properly, food particles can get stuck in your mouth causing bacteria to grow.  The food particles can get stuck between your teeth, on your tongue, along your gums, or on your dentures if you are using one.  The bacteria will then feed on the food particles and leave a foul smell on your mouth.  This sometimes causes morning breath or that unpleasant breath when you wake up.  

What you can do:  Regularly and properly brushing your teeth, flossing, and rinsing well can help keep your mouth clean and free from bad breath.  

Dry mouth

Sometimes, no matter how much you clean your mouth before heading to bed, you still wake up with a bad breath. Why so? Well, it is actually because your mouth gets dry, caused by the naturally decreasing production of saliva while you are sleeping.  Saliva can actually help clean your mouth and remove odor-causing bacteria. Some medications, as well as chronic problems in salivary glands, can also cause dry mouth that makes morning breath worse.

What you can do:  Well, it seems natural to wake up with morning breath, so just make sure to rinse when you wake up to get rid of it.  If you don’t produce much saliva during the day, you can try eating healthy food that needs chewing like carrots, celery, and apples, as well as drinking enough fluids.  You may also use mouth sprays, alcohol-free mouthwashes, or dry mouth moisturizing gel.  Don’t forget to consult your dentist when your mouth still produces foul odor.


Consuming breath-offending food and drinks can also cause your breath to temporarily smell bad. Examples of these food and drinks include garlic, onions, milk, cheese, and coffee. These food, once digested, enter into your bloodstream, and are brought to your lungs, affecting the air you exhale.   

What you can do:  Until the food passes through your body, the odor will stay.  You can temporarily cover up bad breath by brushing, as well as rinsing and gargling with mouthwash.   


If you smoke or orally use tobacco, your breath will smell unpleasant. Tobacco can also result in gum disease, which is another cause for bad breath.

What you can do:   The solution is to simply stop smoking or chewing tobacco-based products.  If you are in the process of kicking the habit, you can temporarily mask bad breath by brushing, gargling with mouthwash, and using a tongue cleaner after each cigarette smoke.  You may also use lozenges, breath mints, or mint gums.   

Mouth infections

Infections in your mouth may also cause bad breath. These infections include mouth sores, tooth decay, surgical wounds from oral surgery, and gum diseases, such as gingivitis and periodontitis.  

What you can do: Consult your dentist on how you can address these mouth infections and also to eliminate bad breath.   

Throat and nose conditions

Do you experience unpleasant mouth odor when you suffer from sinusitis, post-nasal drip, tonsillitis, sore throat, and other similar infections?  These infections and chronic inflammation in your throat, nose, and sinuses can also cause bad breath because of the bacteria they produce.   

What you can do: Consult your doctor on treating throat and nose infections.  Anti-bacterial gargles may also aid in eliminating the bacteria and the smell of your breath.

Gastrointestinal Reflux (GERD)

GERD, also known as gastric reflux or acid reflux, is usually what causes bad breath from the stomach.  This is because of the foul-smelling stomach acid washing back up to your esophagus.

What you can do: Drink plenty of water to refresh your breath.  Water is also less likely to upset your stomach more.  Consult your doctor on how you can treat acid reflux.

Other medical conditions

Bad breath may also result from underlying health conditions.  

  • Cancer and other conditions like metabolic disorders produce certain chemicals that result in distinctive smell in breath.  
  • High ketone levels of diabetic patients cause bad breath.  
  • Excessive urea in the bloodstream of those with kidney problems cause bad breath as a side effect.
  • Severe liver diseases may also cause fetor hepaticus – a condition when you produce a strong smelly breath, caused by sulfur substances being filtered out by your body ending up in the bloodstream and then to your lungs.   

What you can do: Consult your doctor to treat underlying conditions of bad breath.  Drink water regularly to refresh your breath and practice oral hygiene to control bad breath.

How to cure bad breath fast

If you want fast treatment for unpleasant mouth odor,  you need to remember that you are only talking about temporary solutions in masking off bad odor.  These treatments include the following:

  • Mouthwash and anti-bacterial gargles
  • Lozenges
  • Gums
  • Mints
  • Tongue cleaner

If you want to stop bad breath, it is important to find out what may be causing it and address the underlying cause.  Your dentist can help you begin assessing bad breath problems.

The following habits also help in controlling unpleasant breath:

  • Consistently practicing good dental habits like brushing and flossing 
  • Seeing your dentist regularly
  • Drinking water regularly
  • Taking probiotics that may help in dealing with oral health problems
  • Stop smoking and using tobacco-based products

What are some myths about bad breath

Bad breath can be a result of different conditions or habits and can be controlled in different ways.  However, there is a lot of misinformation about bad breath that we can’t tell anymore what is true.  

Here are some myths about bad breath and the truth behind the myths:

MYTH 1:  I can tell I have bad breath by cupping my hands between my mouth and nose.

You can’t always tell you have bad breath by breathing out on your cupped hands.  The bad smell usually originates at the back of your mouth and is released when you speak. If you want to know if you have bad breath, you can ask a family member or a close friend about it.

MYTH 2: I won’t have bad breath because I brush my teeth

Bacteria does not just dwell on your teeth, so brushing your teeth is not always an assurance that you will not have bad breath.  Also, not all parts of your teeth can be reached by your toothbrush, so flossing and rinsing well is also needed to get rid of food particles in between your teeth.  Bacteria can also dwell on your tongue, so you need to make sure you clean your tongue.  Finally, there are many other causes of bad breath that may not be treated by brushing alone, but by addressing the underlying cause.  

MYTH 3:  Mouthwash will get rid of my bad breath

Mouthwash is just a temporary solution to your bad breath.  It’s minty smell may mask unpleasant mouth odor, but it cannot get rid of your bad breath permanently.  Antibacterial mouthwash may also help treat bad breath, but you need to consistently practice the rest of the proper dental hygiene to eliminate bad breath.  Again, it is also important  to address any underlying condition to eliminate unpleasant smelling breath.    

MYTH 4: Bad breath is caused by the food I eat

Well sometimes yes, but maybe no.  As we have mentioned in the causes of bad breath above, the food or drinks that you take in may cause bad breath, but not all the time.  If you just got bad breath after eating a pungent garlicky food, then that may have caused your bad breath.  Chronic bad breath, on the other hand, may be caused by other factors.

MYTH 5: My breath can tell that I have an underlying sickness

Some people say that bad breath is a sign of an illness.  While bad breath can be a side effect of some illnesses like respiratory, digestive, kidney, or liver diseases, it is not always indicative of such diseases.  Some unpleasant smell from the mouth are simply caused by bacteria in the mouth or other causes.  If you are worried about your bad breath, you may consult your doctor to assess the cause of your bad breath.

MYTH 6: Bacteria in the mouth is bad

Bacteria in the mouth is one of the leading causes of bad breath.  However, not all bacteria are bad and harmful.  Infact, oral probiotics have been studied to help reduce the severity of halitosis or bad breath.                

Key takeaways: 

  • Bad breath or halitosis may be caused by bacteria due to poor dental habits; dry mouth; certain food and drinks; tobacco; mouth, throat, and nose infections; GERD; and other medical conditions.
  • The best way to stop halitosis is to identify what causes bad breath and address the condition that caused it. You can start by going to your dentist. 
  • Other ways to control bad breath include practicing proper oral hygiene, drinking water frequently, seeing your dentist regularly, using oral probiotics, and to stop smoking or using tobacco-related products.  
  • There are many myths about bad breath that cause misinformation, including cupping one’s hands to detect bad breath; brushing or using mouthwash to stop bad breath; food is the one causing bad breath; bad breath is a sign of an illness; and that bacteria in the mouth is bad.        


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