Bad breath means that the air you breathe out carries an unpleasant odor. The most common causes are coating on the tongue, bacterial plaque, gum disease and a dry mouth. Cavities, dentures that are not cleaned, tobacco use and certain foods can also cause odor.
Odor that appears in the morning or when you are hungry is usually temporary. Bad breath that continues despite brushing and tongue cleaning, however, needs an examination. That is because the source of persistent breath odor can sometimes be the gums, the nose, the throat or another health problem.
What Is Bad Breath?
The medical name for bad breath is halitosis. The odor usually comes from volatile compounds released as bacteria in the mouth break down proteins. The grooved back surface of the tongue, the spaces between teeth and gum pockets are suitable areas for these bacteria.
Temporary bad breath can occur after sleep, hunger, garlic, onion, spices or tobacco use. Once the trigger is gone, the breath usually returns to normal. With constant bad breath, the underlying cause needs to be identified.
Are Breath Odor and Bad Breath the Same Thing?
In everyday language, breath odor and bad breath describe the same situation. However, not every odor carried on the breath comes directly from the mouth. The nose, the tonsils, the airways and, less often, systemic conditions may need to be considered.
Saliva smelling once it dries does not on its own give a diagnosis of halitosis. Home tests such as licking your wrist or scraping the tongue with a spoon are not reliable. It is also not always easy to judge your own breath accurately.
What Are the Causes of Bad Breath?
The most common reason for a person's mouth to smell is a build-up of bacteria inside the mouth. Although stomach problems are often blamed, most bad breath is related to the tongue, the teeth and the gums.
Causes in the Mouth and Teeth
- Tongue coating: bacteria and food debris that collect on the tongue, especially at the back, can form foul-smelling compounds.
- Insufficient oral care: plaque builds up on teeth that are not brushed regularly and between teeth that are not cleaned.
- Gum disease: bleeding, swollen or receding gums and deep gum pockets can accompany breath odor.
- Tooth decay and infection: deep cavities, an abscess or food trapped around a tooth can cause odor.
- Tartar: plaque can mineralize over time and turn into tartar. Hardened deposits cannot be removed by brushing at home.
- Dry mouth: saliva helps clean the mouth. When saliva decreases, odor-forming substances build up more easily.
- Dentures and appliances: dentures, clear aligners and orthodontic appliances that are not cleaned enough can trap food.
- Tobacco products: they can cause odor directly, increase dry mouth and affect gum health.
Causes That Can Come From Outside the Mouth
Sinusitis, post-nasal drip, tonsil infections and tonsil stones can accompany breath odor. Breathing through the mouth because of a blocked nose also increases dryness. Reflux plays a part in some people, but it is not correct to attribute every case of bad breath to the stomach.
Systemic conditions such as diabetes and kidney or liver disease are rarer causes. Bad breath alone does not give a diagnosis of these conditions. If there are additional symptoms, an assessment by the relevant clinician is needed.
| Cause Group | Findings That May Accompany It | First Assessment |
|---|---|---|
| Mouth and teeth | Tongue coating, bleeding gums, decay, tartar, dry mouth | Dentist |
| Nose and throat | Blocked nose, post-nasal drip, tonsil stones, throat complaints | ENT assessment after a dental examination |
| Digestive system | Heartburn, a sour taste rising into the mouth, reflux complaints | Assessment by the relevant clinician |
| Systemic conditions | Marked thirst, fatigue, weight change or other general symptoms | Assessment by the relevant clinician |
Why Does Bad Breath Persist Despite Brushing?
A toothbrush cannot fully clean between the teeth or the back surface of the tongue. For that reason, brushing the teeth alone is not always enough. Plaque between the teeth, tongue coating or gum pockets can keep the odor going.
An incorrect brushing technique, a worn-out brush, dentures that are not cleaned and a dry mouth should also be considered. If there is decay, an ill-fitting filling, a partially erupted wisdom tooth or gum disease, professional care may be needed.
A situation we see often in our clinic is someone brushing regularly but skipping tongue and interdental cleaning. On the other hand, odor lasting several weeks despite a good care routine should not be put down to poor hygiene alone.
What Causes Bad Breath That Will Not Go Away?
Persistent or chronic bad breath can be caused by gum disease, a thick tongue coating, dry mouth, decay or tartar that cannot be cleaned at home. Using gum or mouthwash without addressing the cause inside the mouth only provides short-lived freshness.
If no clear source is found at the dental examination, sinusitis, tonsil stones, chronic nasal congestion and reflux can be investigated. If there are findings such as constant thirst, frequent urination, unexplained weight loss or marked fatigue, a medical assessment should not be delayed.
Kidney and liver disease can change the odor of the breath. However, these conditions are not common causes of bad breath. Trying to diagnose a disease at home from the character of the odor can be misleading.
Which Vitamin Deficiency Causes Bad Breath?
There is no single vitamin deficiency that directly explains bad breath. A vitamin B12 deficiency can cause redness or tenderness of the tongue or discomfort in the mouth. A zinc deficiency can affect the sense of taste and smell.
These changes can indirectly affect oral care or the perception of odor. A diagnosis of B12 or zinc deficiency cannot be made on the basis of bad breath alone. If there is fatigue, pallor, a sore tongue, numbness or a restricted diet, blood tests should be planned by a clinician. Taking supplements without medical advice is not appropriate.
What Causes Bad Breath in Children?
Common causes of bad breath in children are plaque on the tongue and tooth surfaces, tooth decay, gum problems and a dry mouth. Odor noticed in the morning can be linked to reduced saliva during sleep.
In children who breathe through the mouth because of a blocked nose, allergies or enlarged adenoids, dryness can increase. Tonsil infections, post-nasal drip and tonsil stones can also accompany breath odor. If a child with bad breath has toothache, bleeding gums or difficulty chewing, a dental examination is needed.
In young children in particular, a one-sided, foul-smelling nasal discharge can suggest a foreign body in the nose. In that situation, see a pediatrician or an ENT specialist. Do not try to remove a foreign body at home.
Bad breath in babies can be related to a dry mouth, food residue or infections in the mouth. If there is difficulty feeding, fever, white areas in the mouth that do not wipe away, or fussiness, an assessment by a pediatrician and a dentist is appropriate.
Children should not be given mouthwash made for adults. Because children under six in particular may swallow mouthwash, using such a product should only be considered on a dentist's advice.
How Do You Get Rid of Bad Breath, and What Helps?
Getting rid of bad breath depends on controlling its source. Mints, gum and cosmetic mouthwashes can mask the odor briefly. If there is a problem such as decay or gum disease, lasting improvement should not be expected from freshening products alone.
- Brush your teeth gently with fluoride toothpaste at least twice a day for about two minutes.
- Clean between your teeth every day with dental floss or a suitable interdental brush.
- Clean your tongue once a day, from back to front, without pressing hard.
- Drink enough water during the day. If your mouth is constantly dry, ask for the cause to be assessed.
- Clean dentures, clear aligners and removable appliances according to the manufacturer's and your dentist's advice.
- Avoid tobacco products. Alcohol and heavy caffeine intake can increase dry mouth in some people.
- Keep in mind that onion, garlic and strong spices can cause temporary odor.
- If you have bleeding gums, decay or tartar, do not postpone a dental examination.
In adults for whom chewing is suitable, sugar-free gum can briefly increase saliva flow. Mouthwash does not replace brushing and interdental cleaning. The choice of a therapeutic product should be made with your dentist, taking dry mouth and the condition of your gums into account.
Applying substances such as lemon, vinegar or large amounts of baking soda to the teeth is not recommended. Acidic or abrasive applications can damage the tooth surface and the soft tissues. Antibiotics are also not a routine solution for bad breath; they can only be used with a prescription for a diagnosed infection.
Does Hunger Cause Bad Breath?
During long periods without food, saliva flow can decrease and breath odor can become more noticeable. Ketones formed on a very low-calorie diet can also change the smell of the breath. Once eating resumes and the mouth is cleaned, the odor usually decreases.
Bad breath noticed during Ramadan, between the pre-dawn meal and the evening meal, can be related to the same mechanisms. Drinking enough water between the evening and pre-dawn meals, cleaning the teeth and tongue and keeping up interdental care all help. Odor that continues outside the fasting period needs an examination.
How Is Bad Breath Diagnosed?
The dentist asks when the odor started, at what time of day it increases and whether there is dryness in the mouth. Current medicines, tobacco use, eating habits, reflux and nasal congestion are also assessed.
During the examination, the surface of the tongue, the teeth, fillings, gums, gum pockets and dentures are checked. If needed, X-rays can be used to look for decay or infection. The breath odor is assessed clinically to find out whether the source is inside the mouth.
If no finding in the mouth or teeth explains the odor, an opinion may be requested from ENT, internal medicine or another relevant specialty. This approach helps avoid the unnecessary use of products and medicines.
How Is Bad Breath Treatment Planned?
The treatment plan depends on the cause identified. For tartar and gum disease, professional cleaning and gum treatments can be planned. If there is decay, an ill-fitting restoration or an infection, the tooth involved needs to be assessed.
For a dry mouth, water intake, current medicines and general health are all reviewed. If a prescription medicine is causing dry mouth, it should not be stopped on your own. Speak to the clinician who prescribed it.
If a source in the nose, throat or elsewhere in the body is suspected, a referral is made to the relevant specialty. Products such as gum and mouthwash can help, but they do not replace treating the underlying cause.
When Should You See a Dentist?
See a dentist for bad breath that does not ease within a few weeks despite regular brushing, tongue cleaning and interdental care. The following findings mean the examination should not be postponed:
- Bleeding or swollen gums, or a constant bad taste
- Toothache, a loose adult tooth or difficulty chewing
- Pus, discharge or marked swelling in the mouth
- A sore that does not heal, or a red or white patch
- Pain or a sore under a denture
- A foul-smelling, one-sided nasal discharge in a child
Rapidly growing swelling of the face or neck, fever, or difficulty breathing or swallowing calls for emergency medical assessment. With these symptoms, seek help without delay rather than trying to treat the odor at home.
Frequently Asked Questions
What causes bad breath?
The most common causes are tongue coating, bacterial plaque, gum disease, decay and a dry mouth. Nose and throat problems and some systemic conditions are rarer causes.
How do you get rid of bad breath?
Brushing regularly, cleaning between the teeth and the tongue and drinking enough water are the basic steps. If the odor does not go within a few weeks, a dental examination is needed to find the underlying cause.
Why does bad breath persist despite brushing?
A toothbrush cannot fully clean the back of the tongue or between the teeth. Gum pockets, tartar, decay, dry mouth or nose and throat problems can keep the odor going.
What causes breath odor that will not go away?
Persistent breath odor is usually linked to gum disease, tongue coating or a dry mouth. If no cause is found in the mouth, sinusitis, tonsil stones, nasal congestion and reflux can be assessed.
Which vitamin deficiency causes bad breath?
There is no specific vitamin deficiency that directly explains bad breath. A B12 deficiency can affect the tissues of the mouth and tongue, and a zinc deficiency the sense of taste and smell; a clinical assessment is needed for a diagnosis.
Why does a child's mouth smell?
In children, plaque, decay, mouth breathing, dry mouth and tonsil problems are common causes. If there is a one-sided, foul-smelling nasal discharge, seek medical advice about a possible foreign body in the nose.
Does hunger cause bad breath?
Yes. Reduced saliva flow and the formation of ketones while you are hungry can increase breath odor. Odor that continues outside periods of hunger should be assessed by a dentist.