Can Gum Disease Cause Bad Breath?

If you have, or think you have bad breath (halitosis) and have, or suspect you have gum disease you may be wondering if the two conditions are related. The quick answer is, yes, gum disease can cause bad breath. In fact, 80% of people (1) with gum disease also have bad breath.

This post explains how gum disease leads to bad breath and what you can do to prevent both of these oral issues.

It’s worth noting that whilst gum disease is a major cause of bad breath, there are also some other causes of bad breath which are mentioned below. 

does gum disease cause bad breath

Symptoms Of Bad Breath Caused By Gum Disease

The signs and symptoms associated with gum disease and bad breath include:

  • An unpleasant or offensive odor emanating from the mouth.
  • Taste changes, such as a persistent sour, bitter, or metallic taste.
  • Buildup around teeth, including food particles and plaque.
  • Red, inflamed gums
  • Gums that bleed when you brush your teeth
  • Periodontal Pockets – gaps between the teeth and gums
  • Gum recession
  • Loose, wobbly teeth that may fall out.

In addition to the direct symptoms, individuals with bad breath may notice social reactions from others, such as people distancing themselves, covering their noses, or turning their heads away when in conversation. This can lead to feelings of self-consciousness, embarrassment, or decreased self-esteem.

What Causes Bad Breath?

Bad breath, is primarily caused by bacteria in the mouth interacting with proteins from our food and saliva. These bacteria thrive in areas without much oxygen such as the back of the tongue and in the pockets that form between the teeth and gums. 

The bacteria thrive under layers of food remnants, dead cells, mucus, and other bacteria, both alive and dead. They break down these substances without oxygen.  This process can release volatile sulfur compounds like hydrogen sulfide, methyl mercaptan, Allyl methyl sulfide, and dimethyl sulfide, all of which contribute to bad breath. These odors can resemble the pungent scent of certain chemicals or the foul odor of rotten eggs.

This is often referred to by dentists as Perio Breath

How Does Gum Disease Cause Bad Breath?

As we’ve just highlighted it is oral bacteria, or more specifically their bi-products, that cause foul-smelling breath. The same bacteria and their bi-products are also responsible for triggering gingivitis and its progression to periodontitis. 

Initially, The Bacteria Accumulate

Those with active gum disease often have an accumulation of bacteria along and under the gum line. If the bacterial plaque that coats the gum line isn’t disturbed twice daily, the number of bacteria will increase and so will the bad smell. 

Periodontal Pockets Trap Bacteria

As gum disease progresses, it causes the gums to pull away from the teeth, forming pockets. These pockets can trap food particles, plaque, and bacteria. The deeper these pockets become, the more difficult they are to clean with regular brushing and flossing, leading to an increase in bacterial populations and, consequently, more VSCs and bad breath.

Tissue Death Adds To The Smell

In advanced gum disease, the bacteria and their toxins can lead to the breakdown of gum tissue, ligaments, and even bone. This necrotic tissue can also produce a foul odor.

In some rare cases, a severe type of gum disease, called Necrotizing Periodontal Disease has a similar effect producing an extremely foul breath.

In short, the worse gum disease becomes, the more room there is for bacteria, leading to more bad breath and further damage to the mouth’s structures.

Other Causes of Bad Breath 

It’s worth noting that while gum disease is a leading cause of bad breath, not all cases of bad breath are due to gum disease. Other causes include 

  • Bacterial accumulation on the tongue
  • Poor oral hygiene
  • Tooth decay
  • Dry mouth
  • Smoking and chewing tobacco 
  • Pungent foods, such as garlic, onions, spices, and coffee

While a significant 80-90% of bad breath (2) originates from things within the oral cavity, halitosis can also be caused by things outside the mouth such as 

  • Sinus, Nose, and Throat Issues eg. sinusitis, post-nasal drip, tonsil stones, and other respiratory tract infections 
  • Digestive System Disorders eg. reflux GERD
  • Systemic Diseases eg kidney failure, certain cancers, metabolic disorders, and chronic acidosis 
  • Diabetes 
  • Some medications
  • Fasting and some diets 
  • Foreign Bodies eg. small toys, food particles or pollen lodged in the nostrils 

How To Get Rid Of Bad Breath Caused By Gum Disease

The best way to eliminate bad breath caused by gum disease is to get rid of the bacteria that are causing both the gum disease and the bad odors. 

Now, it’s actually impossible to eliminate all of the bacteria from the mouth, but what we can do is disrupt the plaque bacteria that’s coating the teeth, and gumline and hiding in periodontal pockets. This helps heal the gums, cure gingivitis, stop the progression of periodontitis and get rid of the bad smell.  

The best way to disrupt the bacteria is by 

  • Brushing the teeth twice a day with toothpaste specially designed to target the bacteria that cause gum disease 
  • Cleaning between the teeth each day
  • Cleaning the hard-to-reach periodontal pockets with a gum pocket brush
  • Staying hydrated
  • Refraining from or stopping smoking
  • Controlling blood sugars
  • Eating a healthy balanced diet

Depending on the stage of your gum disease you may need professional gum health treatments.

When To See A Dentist

If you have bad breath and you think it is caused by gum disease it’s important to see a dental professional as soon as you can.

No Dentist? The Gum Disease Guide Can Help!

Beat Gum Disease Now

However, if you don’t have access to a dentist or want to tackle your gum disease at home, you will find a plethora of free information on our home page.  

Then we have our comprehensive guide to beating gum disease

Frequently Asked Questions About Gum Disease and Bad Breath

Can You Get Rid Of Periodontitis Bad Breath?

Yes, by addressing the underlying periodontitis through professional dental treatments and maintaining good oral hygiene, you can significantly reduce or eliminate the associated bad breath. It’s crucial to consult with a dentist for an effective treatment plan.

What Does Gum Disease Breath Smell Like?

Bad breath from gum disease often has a persistent, foul odor, sometimes described as a “metallic” or “rotten egg” smell due to the sulfur compounds produced by the bacteria.

Is Bad Breath From Gum Disease Reversible?

Absolutely. With proper dental care, including regular cleanings and possibly more advanced treatments, combined with diligent home care (like brushing, flossing, and using antimicrobial mouthwash), the bad breath from gum disease can be reversed.

How Do You Get Rid Of Bad Breath From Gum Disease?

To address bad breath from gum disease, one should start with a professional dental cleaning to remove plaque and tartar. Then, maintain a strict oral hygiene routine that includes brushing at least twice a day, flossing daily, and using a therapeutic mouthwash. If gum disease is advanced, additional treatments like scaling and root planing may be recommended.

Can People Smell My Gingivitis?

Gingivitis, an early stage of gum disease, can lead to bad breath due to the bacteria present. If the bad breath is strong or persistent, it’s possible others might notice. However, by catching and treating gingivitis early, you can prevent progression and improve breath quality.

Beat Gum Disease Now


  1. Determining the association between oral malodor and periodontal disease: A case control study – PMC
  2. Periodontitis, Halitosis and Oral-Health-Related Quality of Life—A Cross-Sectional Study – PMC
Sharon Fyles image

Written by Sharon Fyles

Periodontitis Expert & Writer

Sharon Fyles, BSc (Hons, SW), MSc, Dip,  is a Manchester-based expert dental writer specialising in periodontal diseases and their treatment.


Medically Reviewed and Verified by Dr. Gareth Edwards BDS (Hons), MFDS (RCPS Glasgow)

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