Bad Breath Causes,Types,Signs And Symptoms And Its Treatment.

Bad breath, medically called halitosis, can result from poor dental health habits and may be a sign of other health problems. Bad breath can also be made worse by the types of foods you eat and other unhealthy lifestyle habits.

Types of bad breath

If you or your dentist can identify the type of smell in your bad breath, this can help to pinpoint its origin. This oral-systemic link means your dentist may identify potential problems elsewhere in your body – just as an optician can by examining your eyes.

Here are the types of smells different systemic disease bad breath:

  • A cheesy smell usually indicates your bad breath has a nasal origin.
  • fruity smell may indicate uncontrolled diabetes due to increased
  • fishy smell may indicate kidney disease, as increased urea levels can cause a fishy smell such as in  (trimethylaminuria)
  • An acidic smell can be a sign of asthma or cystic fibrosis
  • scent of ammonia can indicate kidney problems
  • A sweet, musty odor may signal liver cirrhosis
  • A fecal odor may point to a bowel obstruction

There are 12 types of ‘bad breath’ caused by disease in your body

  • Tonsil breath
  • Sinus breath
  • Lung breath
  • Gut breath
  • Metabolic breath
  • Diabetes breath
  • Drug breath
  • Liver breath
  • Trimethylaminuria breath
  • Menstrual breath
  • Drug-induced bad breath
  • Halitophobia

1) “Tonsil Breath”: Bad Breath Causes and Your Tonsils

Tonsillitis or tonsil stones may be the cause of your bad breath.


Bad breath linked to tonsillitis can occur in acute, chronic and recurrent forms of tonsillitis.

Your tonsils are two small pads of glandular tissue at each side of the back of your throat. They form part of your immune system, making antibodies and white blood cells to attack germs inside your mouth. They are part of your first line of defense against bacteria in food or air.

The symptoms of tonsillitis include:

  • White or yellow spots of pus on the tonsils
  • A sore throat – pain in the throat is sometimes severe, especially when swallowing, and may last more than 48 hours.
  • Swollen lymph glands under each side of the jaw
  • Bad breath
  • Earache or infection
  • Small children may complain of abdominal pain
  • Headache
  • Loss of voice or changes in the voice
  • A red throat
  • Swollen tonsils, sometimes coated or with visible white flecks of pus
  • Possibly a fever (high temperature)

Around 15-30 percent of tonsil infections are caused by bacteria – usually a streptococcus bacterium (strep throat). Others are caused by viruses. It can be difficult to establish the cause of tonsillitis, so your doctor may do a throat swab (gently rubbing a sterile cotton wool bud over the tonsil) to send for testing.

Antibiotics are only effective against bacteria and won’t cure tonsillitis caused by a virus.

Tonsil stones or ‘tonsiliths’

Sometimes bacteria, food debris, dead cells, mucus, and other materials may get trapped in the crevices in your tonsils. These materials can build up and eventually calcify (harden), forming tonsil stones (tonsoliths). This occurs most often in people who suffer from chronic tonsil inflammations or repeated bouts of tonsillitis. Bad breath (halitosis) that accompanies a tonsil infection is a prime indicator of a tonsil stone.

Patients that have post-nasal problems often report coughing up small, white smelly stones. These, along with throat mucus, indicate nasal problems that may cause bad breath.

Tonsil stones contain compressed sulfur compounds, mucus, and bacteria. One study of patients with chronic tonsillitis tested for volatile sulfur compounds in the subjects’ breath. The presence of these foul-smelling compounds provides objective evidence of bad breath. Researchers found that 75% of people with abnormally high concentrations of these compounds also had tonsil stones.

Other researchers have suggested that tonsil stones should be considered when the cause of bad breath is unclear.

An appointment with an ear, nose and throat specialist is recommended if you have tonsil symptoms and suffer from bad breath.

Remedies and treatment for tonsil stones:

  • No treatment. Many tonsil stones, especially ones without symptoms, require no special treatment.
  • At-home removal. It’s possible to carefully dislodge tonsil stones at home with the use of picks or swabs. Do not attempt to use sharp instruments.
  • Salt water gargles. Gargling with warm, salty water may help alleviate the discomfort of tonsillitis, which often accompanies tonsil stones.

 “Sinus Breath”: Bad Breath Causes and Sinuses

Bad breath can be caused by microbial build, growth or infections your sinuses.

Sinus infection or sinusitis

Sinusitis is an inflammation of the nasal sinuses. It may be a short-term, acute inflammation caused by an infection. Other times it can be a long-term, chronic condition, complicated by allergies and/or structural problems in the nose. Long-term sinusitis can greatly affect your quality of life.

Nasal sinuses are located within the cheeks, around and behind the nose. They act to warm, moisten and filter the air entering the nasal cavity. They also help us vocalize certain sounds.

Symptoms of sinusitis vary depending on the severity and which sinuses are involved. They may go alongside bad breath.

Potential symptoms include:

  • Thick, green or yellow colored mucus from the nose or down the back of the throat
  • Loss of sense of smell or taste
  • Bad taste in the mouth
  • Sore throat/cough
  • Tiredness
  • Temperature or shivers (fever)
  • Facial congestion (a feeling of fullness) and pain
  • Headache
  • Toothache
  • Sensation of pressure that worsens when leaning forward
  • Obstructive sleep apnea
  • Post-nasal drip

Nasal Polyps

Nasal polyps are soft, jelly-like overgrowth of the sinus lining and look like grapes on the end of a stalk.

They do not always cause symptoms. As they usually grow through the tunnel that connects the sinuses to the nose, they often cause a blocked nose.  However, they can also block the airway, which can lead to sinus infections.  These infections can cause bad breath due to run-over of post-nasal drip.

Post–Nasal Drip

Your respiratory system makes a lubricant called mucus.Mucus is a thick, wet substance that moistens your respiratory system and helps trap and destroys bacteria and viruses before they cause infection.

Sinusitis, nasal polyps and post-nasal drip can all cause bad breath as they encourage the build-up of microbes, foreign objects, and metabolites that cause bad breath.

 “Lung Breath”: Bad Breath Causes and Lung Infection

Lower respiratory tract infections

Bad breath can be caused by lung infections and conditions such as bronchitis, pulmonary abscess, tuberculosis, emphysema, and pneumonia.

Types of lung infections include:

  • Bronchitis (infection of the large airways or bronchi)
  • Croup (infection of the trachea or windpipe in children)
  • Influenza (widespread infection of the upper and lower respiratory tract including the nose, throat and, occasionally, bronchi and lungs)
  • Pneumonia (infection of the alveoli and surrounding lung tissue)

Lung cancer usually causes a distinct bad breath, and breath is now being used in early detection.

If lower respiratory tract infection presents with increased mucus production, it may be hard to determine the cause of bad breath.  Unfortunately, aside from treating the source of infection, this type of bad breath may have no other cure than time.


People with asthma are more likely to suffer from dry mouth. This is because asthma restricts air flow, making sufferers more likely to breathe through their mouth. The medication in inhalers can also dry out the mouth and cause irritation, sometimes leading to mouth ulcers or thrush.

Cystic fibrosis

A genetic disease that affects many organs including the lungs, digestive tract, and sinuses.  Patients will have swollen, thick and immobile mucus that leads to sinus blockage in the lungs.

The most common symptoms are respiratory, including a chronic cough, wheezing, and recurrent upper or lower airway infections. Patients with upper respiratory symptoms often have severe nasal polyposis and thick tenacious mucus.

Gut breath”: Bad Breath Causes and the Digestive System

Digestive diseases

The digestive system causes many cases of bad breath. Any condition that allows air from the stomach to move up into the esophagus and the oral cavity may cause halitosis.  However, bad breath caused by the gut is usually a sign of general imbalance in the digestive system.

Digestive causes may include:

  • GERD symptoms or GORD (Gastroesophageal Reflux Disease), which causes acid reflux (heartburn). Any kind of condition that causes stomach acid/heartburn/stomach distress may cause an odor, especially if you’re aware of an unusual taste; this is nearly always accompanied by a smell.
  • Bloating, gas, and burping: any digestive condition that makes you belch (burp) can cause bad breath. These include imbalances seen in digestive conditions like IBS, food intolerances or high sugar consumption.
  • Bowel obstruction or constipation: when your body is not digesting food, an unfortunate side effect can be bad breath that resembles feces.

Metabolic breath”: Bad Breath Causes and Certain Diet Types

Ketone (fat-metabolism) breath

Low-carb or ketogenic diets can force your body to burn fat for fuel instead. This produces chemicals called ketones that are released in the breath, producing an odd fruit-and-nut or acetone odor.

The good news is that if you have bad breath, you’re probably sticking to that low-carb diet well – and often, the bad breath is a short-term problem while your body adjusts to fat metabolism.

Hunger breath

This is caused by regularly skipping meals, or fasting, which can reduce the amount of saliva in your mouth. A dry mouth may prevent clearance of harmful bacteria, causing a sulfuric odor.

“Diabetes breath”: Bad Breath Caused by Insulin 

Diabetics suffer from inadequate insulin production, causing them to burn fat and produce ketones. This means they’re prone to the ‘ketone breath’ discussed above. Another bad breath cause in diabetics may be chronic kidney failure.

Chronic kidney failure

This may cause breath that smells “fishy” or like ammonia. Known as “uremic fetor,” the high amount of urea in the saliva and its breakdown to ammonia causes the smell.

Liver breath”: Bad Breath Causes and Liver Disease

Sometimes, the liver is the source of halitosis.

Frank liver failure leading to hepatic coma is often signaled by a sweet-smelling, musty odor on the breath as the body tries to excrete by-products of sulfur-containing amino acid breakdown. Cirrhosis may cause a breath odor described as decayed blood or rotten eggs.

Late-stage liver failure can also cause bad breath, known as ‘Fetor hepaticus’ – a sweet, musty aroma caused by dimethyl sulfide, not ketones.  This had led Belgian researchers publishing in the Journal of Chromatography suggesting bad breath as a potential diagnostic tool for detecting liver problems.

“Trimethylaminuria breath”: Bad Breath Causes and Genetic Disease

An underdiagnosed disorder, known as TMAU or fish-odor syndrome, may affect as many as 1% of U.S. citizens. It causes a body odor and breath odor that’s often described as ‘fishy’, but sometimes resembles rotting eggs, garbage, or urine.

This genetic disorder affects the ability to break down choline, leading to a buildup of trimethylamine. The fishy odor is excreted via sweat, urine, saliva, blood, and air exhaled through the mouth and nostrils. Patients with trimethylaminuria may need to eliminate or reduce their intake of high-choline foods such as broccoli, beans, eggs, legumes, kidney, and liver.

Menstrual Breath”: Bad Breath Causes and Menstruation

Research have reported that bad breath in women tended to increase before and during their period. They noted that during menstruation, the average female breath odor contained much more VSCs than that of male counterparts. While oral bacteria levels were the same across both genders, women had lower saliva levels during menstruation, which may account for their bad breath.

So, unfortunately, if temporary halitosis tends to arrive at the same time as your premenstrual syndrome (PMS), it’s down to hormonal changes.


Potential causes of bad breath include:

  • Tobacco: Tobacco products cause their own types of mouth odor. Additionally, they increase the chances of gum disease which can also cause bad breath.
  • Food: The breakdown of food particles stuck in the teeth can cause odors. Some foods such as onions and garlic can also cause bad breath. After they are digested, their breakdown products are carried in the blood to the lungs where they can affect the breath.
  • Dry mouth: Saliva naturally cleans the mouth. If the mouth is naturally dry or dry due to a specific disease, such as xerostomia, odors can build up.
  • Dental hygiene: Brushing and flossing ensure the removal of small particles of food that can build up and slowly break down, producing odor. A film of bacteria called plaque builds up if brushing is not regular. This plaque can irritate the gums and cause inflammation between the teeth and gums called periodontitis. Dentures that are not cleaned regularly or properly can also harbor bacteria that cause halitosis.
  • Crash diets: Fasting and low-carbohydrate eating programs can produce halitosis. This is due to the breakdown of fats producing chemicals called ketones. These ketones have a strong aroma.
  • Drugs: Certain medications can reduce saliva and, therefore, increase odors. Other drugs can produce odors as they breakdown and release chemicals in the breath. Examples include nitrates used to treat angina, some chemotherapy chemicals, and some tranquilizers, such as phenothiazines. Individuals who take vitamin supplements in large doses can also be prone to bad breath.
  • Mouth, nose, and throat conditions: Sometimes, small, bacteria-covered stones can form on the tonsils at the back of the throat and produce odor. Also, infections or inflammation in the nose, throat, or sinuses can cause halitosis.
  • Foreign body: Bad breath can be caused if they have a foreign body lodged in their nasal cavity, especially in children.
  • Diseases: Some cancers, liver failure, and other metabolic diseases can cause halitosis, due to the specific mixes of chemicals that they produce. Gastroesophageal reflux disease (GERD) can cause bad breath due to the regular reflux of stomach acids.

Rarer causes of bad breath

As mentioned earlier, the most common reason for bad breath is oral hygiene, but other situations can also be to blame.

Rarer causes of bad breath include:

  • Ketoacidosis: When the insulin levels of a person with diabetes are very low, their bodies can no longer use sugar and begin to use fat stores instead. When fat is broken down, ketones are produced and build up. Ketones can be poisonous when found in large numbers and produce a distinctive and unpleasant breath odor. Ketoacidosis is a serious and potentially life-threateningcondition.
  • Bowel obstruction: Breath can smell like feces if there has been a prolonged period of vomiting, especially if a bowel obstruction is present.
  • Bronchiectasis: This is a long-term condition in which airways become wider than normal, allowing for a build-up of mucus that leads to bad breath.
  • Aspiration pneumonia: A swelling or infection in the lungs or airways due to inhaling vomit, saliva, food, or liquids.


  • If you wear dentures, remove them at night and clean to get rid of bacterial buildup from food and drink.
  • Drink plenty of water and swish cool water around in your mouth. This is especially helpful to freshen “morning breath.”
  • Brush after every meal and floss, preferably twice a day.
  • Replace your toothbrush every two to three months.
  • Arrange regular dental checkups and cleanings.
  • Scrape your tongue each morning with a tongue scraper or spoon to decrease the bacteria, fungi, and dead cells that can cause odor. Hold the tip of the tongue with gauze to pull it forward in order to clean the back of the tongue.
  • Chew a handful of cloves, fennel seeds, or aniseeds. Their antiseptic qualities help fight halitosis-causing bacteria.
  • Chew a piece of lemon or orange rind for a mouth- freshening burst of flavor. (Wash the rind thoroughly first.) The citric acid will stimulate the salivary glands—and fight bad breath.
  • Chew a fresh sprig of parsley, basil, mint, or cilantro. The chlorophyll in these green plants neutralizes odors.
  • Try a 30-second mouthwash rinse that is alcohol-free (unike many off-the-shelf products). Mix a cup of water with a teaspoon of baking soda (which changes the pH level and fights odor in the mouth) and a few drops of antimicrobial peppermint essential oil. Don’t swallow it! (Yields several rinses.)

Raw crunchy foods clean the teeth. Apples contain pectin, which helps control food odors and promotes saliva production. Cinnamon is antimicrobial. Active cultures in yogurt help reduce odor-causing bacteria in the mouth.

  • 1 cup apple chunks
  • 1 cup grated carrot
  • 1 cup diced celery
  • ½ cup dried cranberries
  • ½ cup crushed walnuts
  • 3 to 5 tablespoons plain nonfat yogurt
  • Ground cinnamon

oral factors that can cause bad breath include

– Food impacted between teeth

– Fillings that are old and defective, broken or don’t seal the cavity properly

– Diseases of the dental pulp

– Oral candidiasis

– Throat infections

– Soiled, unhygienic and ill-fitting false teeth. Some non-oral causes may include:

         – Diabetes

         – Kidney failure

         – Infections of the upper respiratory tract and sinuses

         – Nasal cancers

         – Lesions of the nose and back of the throat (nasopharynx)

         – Hiatus hernias

         – Contractions in the throat (oesophageal strictures)

         – Liver failure


  • Brush and floss teeth regularly. Remember to brush the tongue, too, to remove bacteria from its surface. Brushing the tongue can help with bad breath caused by foods a person has eaten.
  • See a dentist regularly for checkups and to ensure dentures or braces are properly fitted and cleaned (and clean dentures thoroughly each night).
  • Quit smoking or using chewing tobacco.
  • Sugarless gum and sugar-free candy can also keep the mouth from drying out.
  • Keep the mouth moist by drinking water and chewing sugarless gum or sugar-free hard candy to stimulate the production of saliva. Eat a diet of foods that need to be thoroughly chewed to keep saliva flowing. Foods that require a lot of chewing, such as apples or carrots, are good options.
  • Over-the-counter mouthwash can help kill bad breath-causing bacteria and may temporarily mask bad breath odors, but it may not treat the underlying cause.

Keep the mouth moist by drinking water and chewing sugarless gum or sugar-free hard candy to stimulate the production of saliva. Mouthwash may temporarily mask bad breath odors, but it may not treat the underlying cause.

Natural remedies used in the treatment of bad breath include chewing on mint or parsley.

If bad breath is due to a health problem such as a sinus infection, diabetes, acid reflux (gastroesophageal reflux disease, or GERD), etc., then the underlying medical issue needs to be treated.

If bad breath is a side effect of taking a medication, discuss with a health care professional whether there are other options for medication that can be taken. Never stop taking a medication without first consulting your health care professional.

For patients who suffer from dry mouth (xerostomia), artificial saliva may be prescribed by a dentist.