Bad breath


bad breath, mouth rot, halitosis, foeter ex ore, dental disease


The human sense of smell is severely restricted compared to animals. While mammals orient themselves based on their sense of smell, humans perceive their environment more through sight. However, smell also plays a role in human relationships. Proof is the saying: “You can't smell each other” for two people who find each other unsympathetic. In addition to the smell of sweat, bad breath is also perceived as unpleasant and foul-smelling. However, the perpetrator often does not notice it and people usually shy away from telling him.

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The term bad breath is generally understood to mean the escape of foul-smelling breath from the oral cavity. Those affected describe the occurrence of bad breath as extremely annoying, most even find it embarrassing.
Unpleasant smelling air is a problem that affects men and women equally. In many cases, the development of bad breath can be observed somewhat more often in older people than in young people.

Although the sense of smell plays a subordinate role in people and sight seems to be the primary sense, unpleasant body odors, such as bad breath, can be repulsive to other people.
Processes that run more subconsciously, for example, control the choice of the ideal partner. The smell of the other person also plays a major role in these processes. In society, sayings like: " Cannot smell each other“This thesis.


The development of bad breath can be triggered by many different factors. In general, so-called systemic and local causes for the occurrence of the bad odor come into question.

The term systemic causes summarizes all reasons that are located inside the organism, for example in the gastrointestinal tract. The local causes for the development of bad breath mainly affect the oral cavity and the nasopharynx. In the majority of those affected, bad breath is caused by local causes.
These causes include, above all, poor and inadequate oral hygiene. Rotting teeth and / or inflammatory processes in the area of ​​the gums cause both a bad taste and a bad smell in the oral cavity. Food residues that settle between the teeth and are not removed regularly can also contribute to the development of bad breath and / or promote tooth decay.
You might also be interested in: How does tooth decay develop?

In many patients suffering from bad breath, inflammatory processes in the area of ​​the oral mucosa or the gums (technical term: gingivitis) can also be detected. Inflammation of the periodontium and / or deep gum pockets in which bacteria settle are often the reason for bad breath.
Although poor oral hygiene and the failure to take regular dental treatments are by far the main causes of bad breath, certain habits also play a crucial role. Above all, the consumption of alcohol (mouthwash containing alcohol also plays a role) and / or nicotine.
In addition, it can be observed that bad breath occurs more frequently in occupational groups that have to speak frequently. In these so-called language professions, there is often a certain dry mouth that promotes the development of bad breath. Furthermore, infections in the oral cavity, for example fungal infections (technical term: candidiasis), can trigger bad breath.

Inflammation of the tonsils, runny nose and other infections of the nasopharynx also contribute to the formation of bad smells. The so-called systemic causes include a variety of diseases. Patients who suffer from diabetes mellitus or are in a diabetic coma often develop a strong bad breath (so-called Ketone odor).
In some cases, a first indication of the underlying disease can even be found on the note of the bad breath. The bad breath of a liver patient has a completely different odor than, for example, the breath odor of a diabetic. If the exhaled air smells increasingly of urine or ammonia, kidney weakness or the onset of kidney failure may be the cause. This special scent note is due to the fact that the urea accumulating in the organism can no longer be properly excreted due to the reduced kidney function.
In the course of this, the urea entered the bloodstream and is exhaled through the lungs, creating the typical ammonia halitosis. Inflammation in the area of ​​the gastric mucosa and cancer of the stomach or esophagus ensure that gastric juice and / or bad smelling gases rise increasingly into the oral cavity and lead to bad breath.

In addition, hiatal hernias and so-called Zenker's diverticula are among the most common causes of bad breath. General disorders of the intestinal flora, caused for example by food allergies or certain medications, are among the causes of bad breath. Certain foods and luxury foods can also be systemic causes of bad breath (for example alcohol and garlic).

A specialty is bad breath in infants. Due to the eruption of the teeth and frequent eructation of the milk ("pork"), bad breath occurs even in the early years of life.
Find out more at: Bad breath in young children

Summary of typical scent notes for certain diseases:

  • Tonsillitis putrid odor
  • Tooth decay / inflammation in the oral cavity putrid odor
  • Diabetes mellitus / diabetic coma Ketone odor (see nail polish remover)
  • Kidney disease Urine or ammonia odor
  • Stomach ailments sour odor

Read more on the topic: Bad breath causes

Mechanisms of formation of bad breath

How bad breath, which is perceived as unpleasant and increasingly embarrassing, is created primarily depends on the respective cause. For this reason, the type and smell of bad breath differs from illness to illness.The American chemist Linus Paulinger (1901-1994) examined several hundred breath samples from patients who took part in a study Bad breath Suffer. He succeeded in detecting up to 200 different compounds in these samples that were mixed with the exhaled air.
Nowadays there are even up to 3000 different connections. These are mainly chemical compounds containing sulfur and nitrogen (for example ketones and ammonia). It is assumed that these compounds are metabolic end products (excretions) of bacteria.


As a rule, patients who suffer from bad breath (Halitosis patients), unable to identify their own exhaled air as malodorous.
This fact is due to the fact that the human sense of smell only responds to changes in the concentration of fragrances. Since the odor concentration remains largely the same in the case of bad breath, the olfactory receptors in the nose only perceive it to a limited extent. In most cases, the immediate environment provides an initial indication of the presence of the bad breath. Various breathing measuring devices are available to scientifically and medically prove the presence of a bad breath problem. These devices are able to measure the sulfur content in the exhaled air and make it visible to the eye.
A quick test can easily be carried out at home by people who are afraid of bad breath. After licking the back of the hand, drying the saliva and then breathing on, if there is bad breath, bad smells can be detected on the back of the hand. In addition, so-called gas chromatography using a Halimeter (Odor meter) in which the concentration of volatile sulfur compounds in the exhaled air is verified.

Food and beverage

Completely different Reasons for Bad breath arise after consuming certain foods or luxury foods. Everyone is familiar with the extremely pungent smell after consuming garlic. The phenomenon is that the person concerned feels nothing, as do all those who have eaten garlic themselves.
A similar odor arises, albeit in a less pronounced form, after eating onions. Also the Drinking alcohol can be smelled in the breath. A criterion that is helpful during police checks. The term alcohol plume is probably familiar to everyone. The air we breathe in smokers, whether cigarette, cigar or pipe smokers, is characteristic.


People who suffer from bad breath often do not even notice it themselves. This fact is due to the fact that the sense of smell is subject to a certain adaptation mechanism. The human sense of smell usually only responds to changes in the concentration of fragrances. However, since the odor concentration is largely constant in the case of bad breath, the odor-sensitive receptors in the nose only perceive it to a limited extent. In most cases, it is the patient's immediate surroundings that provide an initial indication of the presence of malodorous halitosis.

Bad breath can get through though special tests scientifically proven. In medical practice, measuring devices can be used that are able to measure the sulfur content in the exhaled air. It is easier to get rid of bad breath through one Quick testwhich can be done at home to confirm the suspicion.

  1. Back of hand test: As a first step, the person affected should wet the back of the hand with saliva and let it dry out. Then the back of the hand must be breathed on. If there is a bad breath problem, bad smells can be detected in the area of ​​the back of the hand.
  2. Another test: Furthermore, a second test provides good information about the presence of bad breath. The affected person folds his hands as if in prayer. A cavity should then be formed between the two hands and brought close to the lips. Then you have to breathe vigorously into this cavity. The nose can then be used to check whether bad breath can be detected.
  3. Airbag test: The so-called airbag test is also a reliable method for detecting bad breath. During this test, you breathe into a sufficiently large plastic bag that is as odorless as possible. The bag size should correspond to at least a volume of 500ml. Then go to a well-ventilated room and slowly squeeze the bag filled with breathing air in front of your nose.
  4. Cotton swab / plastic spoon test: The cotton swab or plastic spoon test is one of the easiest ways to check the exhaled air for unpleasant odors. A cotton swab is rolled over the back of the tongue (facing the palate) with light pressure. Alternatively, part of the tongue coating can be removed with a plastic spoon. After the sample has dried for about 30 seconds, an odor test can be carried out. A metal spoon is not suitable for this bad breath test.
  5. Saliva test: This test requires collecting approximately 2 ml of saliva in a small glass. After the jar has been closed with a lid for 3 minutes, the odor test can be carried out.


Proper oral care can help.

Since the Bad breath does not represent a disease in itself, but only a symptom of many possible diseases, with the exception of the bad breath caused by food and luxury foods, a prophylaxis specifically aimed at bad breath is not possible. Only eliminating the underlying causes can eliminate bad breath and prevent it from occurring again. Avoiding garlic and onions as well as enjoying them alcohol and smoking, of course, also avoids bad breath, so it is also a prophylaxis.

The question of what can be done against the development of bad breath cannot be answered easily in all cases. If there is a systemic cause, it is usually necessary to initiate targeted treatment of the causal disease.
However, for most local reasons that lead to the development of bad breath there are Tools which can be applied relatively easily. The most important precaution against annoying bad breath is a regular one Oral hygiene.
However, this is not just about that quantity (Frequency) but mainly to the quality (Diligence) des Brushing your teeth on. Basically, teeth should be brushed before going to bed, after breakfast (or after getting up) and after lunch. In the morning and at noon, simply brushing your teeth is usually sufficient to prevent bad breath, but a little more time should be invested in oral hygiene in the evening.

In order to remove even the smallest food residues and plaque deposits in the oral cavity, it is recommended in addition to Toothbrush interdental brushes or Floss apply. This at the same time reduces the risk of inflammation of the gums and / or the gums. Since countless bacteria that can cause bad breath settle on the back of the tongue, it is advisable to clean the back of the tongue at least once a day.
Special mouthwash solutions can also be used. These solutions should be approximate 2-3 times in a row and left in the oral cavity for at least 30 seconds each time. Since the development of bad breath is in many cases based on the drying of the oral mucosa, special liquids can be used as a preventive measure.

Due to the dry mucous membranes, the bacteria within the oral cavity cannot or only insufficiently be transported away and lead to the development of bad smells. The application of these special liquids moisturizes the mucous membranes. Regular chewing of Chewing gum stimulates the formation of saliva and is therefore an effective prophylactic measure. Patients who suffer from frequent bad breath should get their nutrition move. Strongly smelling foods should be avoided as far as possible. Garlic and onions, or the ingredients they contain, stimulate the formation of malodorous gases and thus promote the development of bad breath.

Eliminate / combat bad breath

Since poor oral hygiene is the cause of bad breath in most cases, thorough teeth cleaning is essential. It should be brushed for three minutes at least twice a day. The tongue can also be cleaned with a special tongue cleaner. A lot of bacteria and deposits are deposited on this. The use of dental floss or interdental brushes is very important for thorough oral hygiene. Food residues, the decomposition of which by bacteria can lead to bad breath, are most often deposited in the spaces between the teeth. To prevent bad breath and also tooth decay, the use of dental floss is therefore necessary.

Furthermore, sufficient sugar-free drinks should always be drunk throughout the day. The liquid washes away bacteria and food particles. There are mouthwashes that have antibacterial properties and can thus fight the sulfuric acid-producing bacteria. Furthermore, their taste ensures fresh breath.

How can I test bad breath?

Bad breath, in most cases, is caused by bacteria that break down spokes and food particles. This can produce sulphurous gases that manifest themselves as bad breath. There is a so-called measurement of bad breath Halimeter, a device that can measure sulfur levels.

However, in order to be able to test your own bad breath yourself, a very simple test is recommended. You can rub your tongue over your wrist and then let the saliva dry completely. If you then smell the moistened area, you can clearly see the sulfur compounds and thus draw conclusions about the presence of your own bad breath. The same procedure can be used with a cotton swab. You rub it over the back of the tongue and remove some coating there. A bad breath can then be detected by smelling the stick, since a sulfur odor is also evident here. A doctor can be consulted to clarify the cause of your own bad breath.

Bad breath in children

Bad breath is much less common in children than in adults. The causes of bad breath in children can be very different. Most often, as in adults, it is a sign of poor oral hygiene. Food residues mainly remain in the spaces between the teeth and are broken down by bacteria in the mouth. The metabolic products contain sulfur and cause an unpleasant bad breath.

Thorough oral hygiene is a prerequisite to avoid this. The teeth should be brushed twice a day for at least three minutes. A routine in oral hygiene is very important for children in order to lay the foundation for caries-free teeth.

Furthermore, a dry mouth in children can be the cause of bad breath. This can be caused by stress or medication. Mouth breathing is very common in the children. The bad breath is usually accompanied by an unpleasant taste. It is very important that the children drink enough fluids. Approx. 1 - 1.5 liters of sugar-free drinks per day are recommended.

Finally, bad breath in children can also be a sign of illness. Especially when you can be sure that the child brushes their teeth thoroughly and daily, you should consult a pediatrician if you suddenly experience bad breath. It can be a sign of inflamed tonsils or sinus infections. In rare cases, the liver, stomach, or kidneys can be affected.

More info can be found here: Bad breath in children

Bad breath in babies - what's behind it?

Bad breath can have a variety of causes in babies. In very many cases it is bacteria in the mouth that break down saliva and produce a sulphurous odor. It can also be an infection or inflammation of the oral mucosa.

Diseases in the throat or sinuses can also be the cause of bad breath in babies. Most of the time, it is a question of drinking too little during the day. Even if the baby spits a lot, there may be increased bad breath.

If the bad breath persists despite good oral hygiene, you should consult a pediatrician or a dentist to clarify the cause of the bad breath. Undiscovered diabetes can also be a cause of bad breath. However, this is rarely the case.

In most cases it is bacteria, soon-to-be-erupting teeth or an inflamed area in the mouth.

You can get the baby's bad breath under control with good oral hygiene - i.e. clean your mouth twice a day with fluoridated toothpaste and spread lots of sugar-free drinks throughout the day.

You can get to the main article here: Bad breath in the baby

Bad breath in pregnancy

Bad breath during pregnancy is not uncommon and is very often associated with inflammation of the mouth. The body changes during pregnancy. Among other things, the mucous membrane in the mouth changes. The blood supply to it is increased through hormonal changes and it swells slightly. This makes it easier for food particles and bacteria to accumulate. There is increased inflammation of the gums (Pregnancy gingivitis).

Bad breath is a typical sign of inflammation. Good and extensive oral hygiene is therefore particularly important during pregnancy. To relieve bad breath you can rinse with chamomile tea several times a day. Many other mouthwashes contain alcohol. For this reason, these mouthwashes should not be used during pregnancy. If the bad breath persists, you should visit a dentist to prevent the consequences of persistent gingivitis (= inflammation of the gums).

... after almond surgery

Bad breath after almond surgery is very common. The reason often lies in not brushing your teeth in order to protect the wounds that have not yet healed. It is often advised to be very careful with your teeth and not brush the wound areas for a few days. This is to minimize the risk of rebleeding. A bad breath that develops quickly is completely normal, as the bacteria present in the oral cavity decompose the now increasingly deposited food residues. There is a sulphurous odor.

Drinking a lot and rinsing your mouth frequently, for example with lukewarm chamomile tea, can help. If the bad breath persists, you should visit the treating dentist for advice on possible medical mouthwashes or antibiotics. Often you get an antibacterial mouth rinse for the days when oral hygiene is restricted. In general, however, the halitosis subsides as soon as the wounds have healed and the usual thorough dental care consisting of brushing your teeth, interdental brushes and flossing can start again.

Learn more at: Have the almonds removed?

... in the morning

Many people suffer from bad breath, especially in the morning. The reason for this phenomenon are bacterial pathogens on the tooth surface, the mucous membranes and above all the tongue, which produce unpleasant smelling gases during the night by secreting various metabolic end products. However, this bad breath can be reduced or even avoided entirely with simple tricks. To prevent bad exhaled air in the morning, regular oral hygiene should be performed before going to bed. In addition to cleaning teeth with a toothbrush, cleaning the interdental spaces is essential.

The thorough use of interdental brushes ensures that fewer bacterial pathogens remain in the oral cavity and produce nasty smells that are perceived as bad breath in the morning. In addition, household vinegar dissolved in water, with which the oral cavity is rinsed out about 4 to 5 times a day, can have a positive effect. Bad breath in the morning is also particularly common after consuming strong-smelling foods such as garlic or onions.

In order to prevent bad smelling exhaled air in the morning, you should refrain from eating such food. In addition, it must be taken into account that the frequent consumption of alcoholic foods or drinks drastically increases the risk of bad breath in the morning.Those affected are therefore advised to reduce alcohol consumption to a minimum. Many people who have bad breath swear by the effects of ginger or apples. With regular consumption before going to bed, bad breath should occur much less frequently in the morning.

Read on under: Avoid bad breath in the morning

... while fasting

It is not uncommon to experience a strong bad breath while fasting. While this is not necessarily the case, it is very common. Usually, bad breath is most commonly caused by bacteria in the oral cavity that break down remaining food particles and saliva. In the process, they produce sulfur-containing compounds that cause bad breath.

Fasting also means that the body excretes toxins. Toxins are eliminated through the bladder, intestines, skin and mucous membrane. Excretion through the mucous membranes can cause bad breath. In order to avoid bad breath during the fasting period, it is advisable to drink a lot during this time. As a result, the toxins are increasingly excreted in the urine and the mouth is moistened at the same time. It is best to drink tea, as there are varieties that support pleasant breath (e.g. sage, fennel or anise). In general, extensive and thorough oral hygiene is particularly important during Lent. In the case of bad breath, you should brush your teeth once more a day.

... like ammonia

You can test your own bad breath yourself using various methods. To do this, moisten your own wrist with your tongue or run a cotton swab over it. If you then smell the previously moistened area, it is possible that you will smell ammonia. If you can clearly identify this smell as such, you should consult a doctor as soon as possible. Breath that smells of ammonia is a sign of kidney weakness or kidney failure. In this case, your own urine also smells strongly of ammonia. This is due to too high a level of urea in the body. The kidneys normally excrete these substances in the urine. If the kidneys no longer function properly, the substances enter the blood and are exhaled through the lungs. The result is breath that smells of ammonia.

For more information, read on here: Kidney disease

... after acetone

Breath that smells of acetone can have two reasons. On the one hand, this can be an indication of diabetes or, on the other hand, it can be caused by fasting. Diabetics whose breath smells of acetone must be treated as soon as possible. Diabetics have to supply themselves with artificial insulin in order not to fall into a diabetic coma after eating because of an excess of sugar. The body would then accumulate too much toxic acetone. When fasting, the body draws on the body's own energy stores and converts the released fatty acids into acetone. This is then excreted in sweat, urine and breath. Acetone smells like e.g. Nail polish remover.

... through tooth decay

Bad breath can also be caused by tooth decay = tooth decay. The tooth decay itself does not cause any odor - however, trapped food residues that cause tooth decay do. Tooth decay is therefore an indication of food particles that are often left behind and poor oral hygiene. These in turn are the causes of bad breath.

The caries bacteria decompose food components whose metabolic products can also smell unpleasant.

... through tartar

Bad breath is caused by a large number of bacteria in the oral cavity that break down food particles and produce sulfur-containing compounds. These bacteria are also the cause of tartar build-up. Tartar can also be the reason for bad breath. Tartar develops at different rates in every person and can have different causes. These include, for example, the composition of the saliva and the position of the teeth. After a professional tartar removal as part of the professional teeth cleaning at the dentist, the bad breath also disappears.

... through liver disease

If the liver is dysfunctional, the bad breath can be described as sweet. Liver failure can result from viral hepatitis or poisoning. Poisoning can result from medication, chemical substances, mushrooms or drugs. Acute liver failure occurs very rarely in Germany. One of the symptoms is a sweet smelling bad breath that does not go away despite good oral hygiene. In addition to bad breath, symptoms such as confusion, sleepiness, Tremble and Impaired consciousness on. If you have a special smelling bad breath and / or the symptoms described above, you should consult a doctor quickly.

Read more about this at: Liver disease

... through illness of the stomach

Bad breath can also result from diseases or inflammation in the gastrointestinal tract. A common cause of bad breath is heartburn. Here, chyme and stomach acid flow back into the esophagus and cause an unpleasant acidic belching and an unpleasant taste.

Rare causes of bad breath are one gastritis (= Inflammation of the stomach lining), stomach ulcers or stomach cancer. In the case of these diseases, bad breath would inevitably be accompanied by symptoms such as severe weight loss in a very short time, severe stomach pain or fatigue.

Learn more at: Diseases in the gastrointestinal tract

... like garlic

Everyone knows a strong bad breath after a meal rich in garlic. When consumed, the substance becomes Allicin released, which is responsible for the unpleasant odor. The smell is very persistent and accompanies you all day and sometimes even through the night.

Home remedies to get rid of the garlic plume quickly include a glass of milk, green tea, biting a piece of lemon, chewing fresh herbs or using other spices such as Caraway seed. After about 24 hours, however, you can usually get rid of the smell.

Which doctor treats bad breath?

In general, every dentist will advise on possible therapies in the event of bad breath. He first looks for possible causes for the development of bad breath and then advises on the possibilities of treatment. Bad breath can have different causes. Inflammation of the gums, tooth decay, poor oral hygiene and plaque on teeth and tongues can cause bad breath. If the symptoms of bad breath occur and persist for a long time despite good oral hygiene, it is recommended to visit an ENT specialist or a dentist, because bad breath can come from both areas.

Medication for bad breath

There are various active ingredients in over-the-counter medicines and medicines available at pharmacies that are used to combat bad breath. These active ingredients include Cetyl pyridinium chloride, this in Dobendan-solution is included, and Hexetidine, which in a drug named Hexoral or Hexoral Spray is available. There is also the active ingredient Chlorophyll. This is contained in the Stozzon Chlorophyll Dragees used for bad breath. In general, there are many home remedies that can be used to combat bad breath and represent a natural alternative to medication.

Home remedies for bad breath

In general, medical mouthwashes from the pharmacy help against bad breath because they work against the bacteria responsible for bad breath. However, if you want to try to fight bad breath naturally, there are various home remedies that can be used.

You can rinse your mouth regularly with lukewarm sage tea. Gargling with tea tree oil dissolved in water has also proven helpful. The same can be done with apple cider vinegar dissolved in water. An old home remedy for bad breath is chewing fresh mint leaves. Furthermore, the so-called oil pulling is a widely used home remedy. It is said to help with gum problems, bad taste in the mouth, plaque on the tongue and bad breath. To do this, a tablespoon of cold-pressed sunflower oil is pulled through the teeth on an empty stomach for 15 minutes in the morning. It turns into a white liquid and is then spat out into a paper towel. There are so many different home remedies available to combat bad breath.

But not every home remedy works the same for every patient. Therefore, you may have to try one or the other remedy until the right one is found for you.

For more information on this topic, read also: Home remedies for bad breath


Bad breath is not a disease, but a symptom of many different causes. These can be located directly in the oral cavity or they can also be the result of diseases away from the mouth. Certain foods and beverages can also lead to bad breath. Therapy, or rather the elimination of bad breath, takes place primarily through the rehabilitation and care of the teeth and the oral cavity, while the therapy of diseases far from the mouth is reserved for the specialist or family doctor.