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What Causes Bad Breath? 9 Ways to Improve Halitosis

Medically reviewed by Carmen Pope, BPharm. Last updated on May 11, 2023.

Official answer

by Drugs.com

Bad breath, also known as halitosis, is breath that has an unpleasant odor. The person with the bad breath often doesn't realize how bad their breath smells, because they have got used to it. Not so for others, who get a full blast when their companion speaks, laughs, or exhales. Read on to find out why some people develop bad breath and what can be done to prevent it.

Causes

1. Morning Mouth and Lack of Saliva: The Unpleasant Start To The Day

Bad breath can be caused by a decreased flow of saliva. Saliva plays an important role in digestion and helps to remove odor-causing particles in the mouth.
Bad breath when you wake up is considered normal. This happens because the saliva that regularly washes away decaying food and odors during the day diminishes at night while you sleep. Your mouth becomes dry and dead cells stick to your tongue and inside of your cheek. Bacteria use these cells as a food source and expel foul-smelling gases.

2. Nasty Bacteria and Gum Disease

Gum disease can be a contributing factor to halitosis. Early gum disease is called gingivitis and is an inflammatory response to a build-up of bacteria found in plaque that has not been properly removed from the teeth. Plaque builds up because of poor brushing and flossing. Once plaque is established, it can only be removed by your dentist or hygienist.

Plaque is essentially a reservoir of bacteria. These bacteria can migrate to other parts of the mouth - especially the tongue - and are thought to be responsible for a significant amount of halitosis. Poor oral hygiene and high-sugar diets can also lead to cavities which contribute to bad breath.

3. Dieting Fads: High Protein, Low Carbs

High protein, low-carb diets like Dr. Atkins can cause your body to burn fats for energy instead of carbs which can lead to a condition called ketosis.

Ketosis is the state the body finds itself in when it is using fats as its main fuel. In addition to low-carb or ketogenic diets, ketosis can occur with intermittent fasting as well.

Ketosis is characterized by high levels of ketones in the blood. The body can use these for fuel, and their presence gives the breath a subtle, sweet smell like fruit or acetone in nail polish remover.

Ketosis is not the same as ketoacidosis which is a dangerous and potentially fatal condition that may occur in people with diabetes.

4. Culprits: Food Offenders, Smoking, Alcohol, and Medicines

Garlic, onions, fish, and coffee are obvious causes of bad breath, as are beverages that dry out the mouth, such as alcohol because they reduce levels of saliva needed to wash away odor-causing bacteria. Regularly drinking water, particularly at meal times; chewing sugar-free gum after meals; and adding a squeeze of lemon to fish dishes can help reduce food odor.

Smoking is also a notorious cause of bad breath. Smoke particles remain in the lungs, long after you have finished that last drag, making your breath smell pungent and stale. Smoking also dries out the mouth contributing to gum disease and dental decay.

Many medicines are associated with bad breath, usually because they dry out the mouth. Offenders include antihistamines, sedatives, amphetamines, antidepressants, diuretics, decongestants, anticholinergics, and some antipsychotics. Certain vitamin supplements (especially in high doses) are also culprits.

5. Could It Be A More Serious Medical Condition?

Bad breath should not be taken lightly. Sometimes bad breath can be a sign of a more serious illness.

Ketoacidosis (as mentioned previously) in poorly controlled or undiagnosed diabetics can cause a fruity smell on the breath. It is caused by a lack of insulin and can be potentially fatal.

Gastroesophageal reflux disease (GERD) can also contribute to bad breath, due to small amounts of partially digested food being regurgitated back up the esophagus, or an inefficient movement of food out of the stomach into the small intestine.

Sinus or respiratory tract infections may also have bad breath as a symptom. Chronic kidney failure can produce an ammonia-like odor because toxins are excreted through the lungs.

Treatment. Bad Breath Be Gone: Here’s What You Can Do

Good oral hygiene is the key to fresh breath. The main treatment for bad breath is looking after your mouth.

  • Brush and floss twice a day, every day.
  • Use mouthwash frequently or a water flosser with mouthwash added to it.
  • Scrape your tongue.
  • Stay hydrated - a dry mouth can exacerbate bad breath.
  • Watch what goes in your mouth
  • Mouthwashes and other treatments
  • Probiotics: A different way to treat bad breath
  • Do not smoke or chew tobacco.
  • Regularly plan a visit to your dentist.

1. Brush your teeth at least twice-a-day.

You should spend at least two minutes brushing to make sure you get to those hard-to-reach places. Pay extra attention to the areas where the tooth reaches the gum. Electric toothbrushes are more effective than manual toothbrushes in removing plaque.

The best time to brush your teeth is usually just after you eat to reduce the levels of bacteria that cause tooth decay and bad breath. However, food and drinks that are acidic (especially fizzy drinks and fruit juices), and coffee in particular, can soften enamel, and brushing too soon after consuming them can damage the enamel. In this case, it is best to wait 30 minutes before brushing to allow the enamel to harden.

2. Make A Date With Your Floss

Do you floss every day? You probably hear that question at the dentist. Certainly, you are always truthful, right?

It's never too late to start. Flossing is best performed after brushing; twice a day is best but once a day is better than none. Dental floss or interdental brushes can be used. The goal is to clean the areas where your toothbrush cannot reach and to clear the spaces in between your teeth. The gum stimulation is good for your gums, too. If you are not sure how to do this, ask your dentist or dental hygienist to show you the best way.

3. Tongue Scraping and More

Sounds painful, but it's not. This is done using a tongue scraper or a soft toothbrush. You need to place it as far back on the tongue as possible and scrape forward to clear off any coating. It’s best done once a day after brushing and flossing.

You could also consider using a mouthwash like Cepacol or Listerine after you have brushed, flossed, and scraped, or add some mouthwash to your water flosser reservoir. A mouthwash helps to kill bacteria or neutralize any chemicals that cause bad breath.

4. Keep Your Mouth Moist: Drink Plenty of Water

Drinking plenty of fluids, particularly water, helps to keep your saliva flowing. A swish of water after eating can loosen food particles. Sugar-free gum after each meal may also help to increase saliva flow and prevent plaque from forming as well as keeping your breath fresh.

Artificial saliva substitutes may also be used in people prone to a persistent dry mouth if deemed necessary.

5. Watch What Goes In Your Mouth

Several foods are notorious for adding extra unwanted aromas to the breath.

Garlic, onions, fish, coffee, and spicy foods are some of the more common culprits. But luckily, bad breath from these foods is usually temporary and a quick brush of your teeth and a swirl of mouthwash will typically ease the odor.

Foods that have been shown to help improve the smell of your breath include apples, fresh herbs, ginger, greens, melons, cinnamon, and green tea. Chewing on fennel seeds not only increases saliva flow but also helps neutralize offensive odors and aid digestion. Plus they are naturally antibacterial.

6. Mouthwashes and Other Treatments

Good oral hygiene is the most effective way of treating bad breath. In conjunction with good oral hygiene, prescription, and OTC products may also be beneficial.
Mouthwashes that contain antibacterial agents cetylpyridinium chloride (Cepacol), chlorhexidine (Peridex), or hydrogen peroxide are effective.

Closys, a toothpaste, mouthwash, and oral spray hygiene system is another option.

These products kill the germs that cause bad breath and freshen your breath. If bad breath is due to GERD, drugs such as H2 blockers, proton pump inhibitors (PPIs), or antacids may also be recommended.

7. Probiotics: A Different Way To Treat Bad Breath

Some experts advocate the use of probiotics to help clear bad breath, rather than products that are designed to kill bacteria (such as mouthwashes).

More than 700 different strains of bacteria have been found in the human mouth, although most people only host 34 to 72 different varieties. Most are harmless and aid in food digestion. Some, such as Streptococcus mutans and Porphyromonas gingivalis have been linked to tooth decay and periodontitis.

One type of bacteria has been designated super-hero status. People with high levels of S. salivarius in their mouth have little, if any, tooth decay. S. salivarius has been shown to crowd out odor-causing bacteria and can help eliminate bad breath. The trouble with mouthwashes is that they tend to kill all bacteria, both good and bad.

Oral care probiotics that contain high numbers of S. salivarius K12 and/or S. salivarius M18 bacteria can help restore levels of healthy bacteria in your mouth. Both these strains help maintain good oral health and limit both bad breath and tooth decay.

8. Do not smoke or chew tobacco.

Research has shown that smoking does exacerbate bad breath because it can increase the production of toxic volatile sulfur compounds in diseased periodontal pockets. Smoking also leaves a stale scent in your mouth that is created by cigarette smoke lingering in your throat and lungs.

9. Regularly Plan a Visit To Your Dentist

Prevention is the key to a healthy mouth. You should visit your dentist regularly, usually every six months, to have your teeth examined and cleaned. This will help to prevent gingivitis, cavities, and other oral issues.

If you have a problem with bad breath, your dentist can help determine the cause, provide advice, and determine treatment. It may be that regular cleaning, flossing, and a daily mouthwash may be all that's needed. Your dentist can also refer you to a doctor if warranted.

References
  • Kauss, A. R., Antunes, M., Zanetti, F., Hankins, M., Hoeng, J., Heremans, A., & van der Plas, A. (2022). Influence of tobacco smoking on the development of halitosis. Toxicology reports, 9, 316–322. https://doi.org/10.1016/j.toxrep.2022.02.012
  • Bad breath. Mayo Clinic. 2023. https://www.mayoclinic.org/diseases-conditions/bad-breath/symptoms-causes/syc-20350922
  • Bad breath: What causes it and what to do about it. Harvard Health Blog. Jan 21, 2019. https://www.health.harvard.edu/blog/bad-breath-what-causes-it-and-what-to-do-about-it-2019012115803

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