Bad Breath and Tonsil Stones: Detailed Guide

Author: Op. Dr. Javidan Asafov · ENT / Otolaryngology Specialist · Last medical review: 04.10.2026

How does bad breath develop?

Some of the bacteria living in the mouth and throat break down food debris, shed cells and secretions in sheltered, low-oxygen areas (the back of the tongue, gum pockets, the tonsil pits). In doing so they release gases called volatile sulphur compounds, which smell like rotten eggs or cabbage. Saliva constantly washes these areas and limits bacterial growth. That is why anything that reduces saliva, such as sleep, long periods without eating, mouth breathing and medicines that dry the mouth, makes the odour worse.

Temporary and persistent bad breath

Morning breath is caused by reduced saliva flow at night; it clears with breakfast, drinking water and brushing and is not a sign of disease. The odour from garlic, onions, spicy food, alcohol and smoking is also temporary; some foods pass into the blood and are breathed out through the lungs, so brushing may not remove their smell straight away. Long periods without food during dieting or fasting can also give the breath a different smell. Odour that lasts all day and does not clear with oral care, however, is persistent bad breath, and its cause should be investigated.

Causes in the mouth and teeth

The most common source of persistent bad breath is the mouth. The whitish coating at the back of the tongue, gum inflammation and gum pockets, tooth decay, and dentures or bridges that are not cleaned well all cause odour. These causes are treated with regular oral care and dental check-ups. If the odour continues even though the mouth and teeth are healthy, an ear, nose and throat examination is needed.

Ear, nose and throat causes

Tonsil stones and chronic tonsillitis

Because of the deep pits (crypts) on their surface, the tonsils are an area where debris and bacteria can easily collect. Frequent tonsil infections make these pits deeper. Over time the debris collecting in the pits hardens to form tonsil stones. Even without stones, chronic tonsillitis can cause cheesy deposits on the tonsil surface, a bad taste and odour.

Sinusitis and postnasal drip

In chronic sinusitis or long-lasting nasal inflammation, thick, infected mucus drips from the sinuses and the back of the nose into the throat. This mucus collects at the back of the tongue and in the throat, becomes food for bacteria and causes odour. A constant need to clear the throat, a bad taste in the mouth in the morning and a feeling of postnasal drip point to this cause.

Nasal blockage, snoring and dry mouth

People whose nose is blocked because of a deviated septum, enlarged turbinates or, in children, enlarged adenoids breathe through the mouth. Mouth breathing and snoring, especially during sleep, dry the mouth, remove the cleansing effect of saliva and clearly worsen morning breath. Drinking too little water, older age and some medicines (such as some allergy, blood pressure and antidepressant medicines) also contribute to dry mouth.

Reflux and silent reflux (laryngopharyngeal reflux)

Reflux is the backflow of stomach contents into the oesophagus. In some people the stomach contents reach as far as the throat and larynx; this is called laryngopharyngeal reflux. Because this type of reflux often causes no obvious heartburn, it is also known as “silent reflux”. A sour or bitter taste in the mouth, belching, a burning or lump-like feeling in the throat, a constant need to clear the throat, a feeling of postnasal drip, morning hoarseness and a dry cough are common symptoms. Stomach contents reaching the throat, and the thick secretions they cause, provide extra food for the bacteria collecting at the back of the tongue and in the throat and can contribute to the odour. Eating late at night, fatty and spicy food, excess weight, smoking and alcohol make reflux worse.

A foreign body in a child’s nose

In young children, a foul-smelling, sometimes bloody discharge from one nostril, together with bad breath, may be a sign of a bead, paper or piece of food stuck in the nose. The object then needs to be removed during an examination with a suitable method; trying to remove it at home can push it deeper.

Other causes

Apart from reflux, bad breath caused by stomach disease is much rarer than is commonly believed; if stomach complaints are prominent, the stomach and oesophagus may need to be assessed separately. Uncontrolled diabetes can cause a fruity or acetone smell, and advanced kidney and liver disease can cause characteristic breath odours. Rarely, sores and masses that do not heal in the mouth, throat or nose can also cause a bad smell. For this reason, long-lasting bad breath should be assessed with a thorough examination.

Tonsil stones: symptoms and treatment

Tonsil stones are usually white or yellowish particles about the size of a grain of rice, soft or hard in texture. Some people can see them in the mirror, while in others they stay deep in the tonsil pits and are found only on examination. They can cause bad breath, a bad taste in the mouth, a feeling of something stuck in the throat, mild pain on swallowing and, at times, pain spreading to the ear. Particles that drop out on their own when coughing or gargling and smell very bad when crushed are typical.

Small stones that cause no symptoms need no treatment. Gargling with warm salt water after meals, good oral care and drinking enough water reduce stone formation. Poking at stones with a toothpick, cotton bud, fingernail or hard objects is not recommended, as it can cause bleeding, infection and further deepening of the pits. If stones recur often, cause constant bad breath and a feeling of something stuck in the throat, or if the person has frequent tonsil infections, removing the tonsils (tonsillectomy) provides a permanent solution to the stones.

Examination and assessment

Assessment starts with a detailed history: how long the odour has been present, whether it changes through the day, whether people around you notice it, your oral care habits, nasal blockage, postnasal drip, snoring, reflux symptoms such as heartburn, a sour taste and belching, general illnesses and the medicines you use. Not using perfume, scented cosmetics, mouthwash or mints, and avoiding foods such as garlic and onions, for a few hours before the visit makes assessment easier. The mouth, tongue, gums and tonsils are examined, checking the tonsil pits for stones or deposits. The nose, the back of the nose and the larynx are assessed endoscopically with a thin camera, also looking for signs of irritation caused by reflux in the larynx, such as redness and swelling. A sinus CT scan and blood tests are requested if needed.

Treatment

Oral care

Brushing twice a day, cleaning between the teeth with floss or interdental brushes and gently scraping the back of the tongue from back to front with a tongue scraper are the most effective measures against odour. People who wear dentures need to clean them every day. Drinking enough water during the day, not going without food for long and chewing sugar-free gum increase saliva flow. Alcohol-based mouthwashes can dry the mouth; mouthwashes do not replace oral care.

Treating ear, nose and throat causes

Chronic sinusitis and postnasal drip are treated with nasal rinsing and medicines and, when needed, endoscopic sinus surgery. A deviated septum is corrected with septoplasty, and turbinates that have not shrunk with medicines are reduced. Opening the nose reduces mouth breathing and dry mouth. In children, enlarged adenoids are assessed in a way suited to the child’s age.

Treating reflux

The basis of reflux treatment is adjusting diet and lifestyle: finishing the evening meal at least two to three hours before bed, eating smaller meals more often, cutting down on fatty, fried and spicy food, chocolate, coffee, fizzy drinks and alcohol, stopping smoking, losing excess weight and raising the head of the bed slightly all clearly reduce symptoms. If needed, medicines that reduce stomach acid or limit the backflow of stomach contents are used on medical advice. In silent reflux, throat and larynx symptoms can take from a few weeks to a few months to settle.

Tonsillectomy

Removal of the tonsils may be recommended for frequently recurring tonsil stones that cause symptoms, for chronic tonsillitis accompanying the stones, or for frequent tonsil infections. The operation is performed through the mouth under general anaesthesia and leaves no visible scar. In adults, recovery usually takes one to two weeks; there is a sore throat during this time, and soft, lukewarm or cold foods are eaten. Because there is a risk of bleeding in the first weeks after surgery, the doctor’s instructions must be followed carefully. The decision to operate is made by considering the severity of the symptoms and the person’s general health together.

Halitophobia: believing you have bad breath when you do not

Some people are sure their breath smells even though no one around them notices any odour and no cause is found on examination. Behaviours such as covering the mouth when speaking, keeping away from people and constantly using mouthwash or mints can make daily life difficult. This is called halitophobia. Showing through a thorough examination that there is no odour reassures most people; if the anxiety is marked and persistent, psychological support can also help.

Frequently asked questions

Does bad breath come from the stomach? Usually not. Most persistent bad breath comes from the mouth, and a large part of the rest from the tonsils, nose and sinuses. Odour from the stomach is much rarer than is commonly believed; however, reflux, especially silent reflux reaching the throat, can contribute to the odour in some people and can be treated.

Can I remove tonsil stones myself? Stones that drop out on their own are not a problem, and gargling with salt water helps this. But poking at the tonsil with a toothpick, cotton bud or fingernail can cause bleeding and infection, so it is not recommended.

Will a tonsillectomy cure my bad breath? If the odour comes from tonsil stones or chronic tonsillitis, it brings clear improvement in most people. If the source is the teeth, tongue or sinuses, tonsillectomy alone is not enough, which is why other causes are assessed before surgery.

Do mouthwashes help? Mouthwashes can mask the odour for a few hours but do not remove its cause. Alcohol-based mouthwashes can dry the mouth and increase the odour in the long run. Gargling with warm salt water is useful for tonsil stones.

My child has bad breath. What could the cause be? In children the most common causes are mouth breathing due to enlarged adenoids and tonsils, sinusitis and inadequate dental care. A foul-smelling discharge from one nostril may mean a foreign body in the nose and needs examination without delay.

My breath smells in the morning. Is that normal? Yes. Because saliva flow decreases at night, everyone has morning breath, and it clears with breakfast, drinking water and brushing. Odour that lasts all day is not normal, and its cause should be investigated.

This article is for general information; please consult your physician for diagnosis and treatment.