Bad Breath: Main Causes

Unpleasant breath odor (halitosis) is a very common complaint. The cause may lie in the oral cavity itself: plaque, gum disease, holes in the teeth, or infection. We explain what causes bad breath, which diseases underlie it, and which doctor to see if self-care does not help.

Bad Breath: What It Is and How Common It Is

Halitosis is the generally accepted term for unpleasant breath odor. It occurs very often, and there are many causes: strong-smelling food and drinks, smoking, problems with teeth and gums, dry mouth, tonsillitis and acid reflux from the stomach, fasting and crash diets, certain diseases and medications. Therefore, the same symptom in different people is explained differently, and the discussion of the cause begins with the oral cavity.

Dental Causes: Plaque, Cavities, Gum Disease

The main mechanism is bacteria: they accumulate in the mouth, on the teeth, on the tongue, and in the spaces between the teeth and release substances with an unpleasant odor. Dental causes include gum disease, holes in the teeth (cavities), and infection in the oral cavity. If the cause is in the teeth or gums, treatment by a dentist may help; problems with dentures are also a reason to see a dentist.

Dry Mouth

Dry mouth is considered a medical cause of halitosis.

General Causes: ENT Diseases, Stomach, Metabolism

Not everything is resolved in the mouth. Sinusitis and other nose problems, tonsillitis, and acid reflux from the stomach (reflux) also cause unpleasant odor. Certain diseases and medications give the breath a specific note. Strong-smelling food and drinks — raw onion, garlic, cabbage, hot spices — have a temporary effect, while smoking creates its own persistent odor. If the cause is not in the oral cavity, treatment of the underlying disease may help — that is, the condition itself is addressed first.

Bad Breath During Fasting and Strict Diets

Fasting and crash diets with severe food restriction are a separate item in the list of causes of halitosis, along with food, smoking, and oral diseases.

How the Cause Is Determined and When a Doctor Is Needed

During an appointment, the doctor assesses the condition of the teeth, gums, tongue, and dentures; if necessary, refers to other specialists. Such an examination helps determine whether the odor is related to the oral cavity. The scope of examination depends on the findings at the appointment and is determined by the doctor.

You should see a dentist if:

• the odor does not go away after several weeks of routine oral care;
• the gums are painful, bleeding, or swollen;
• a tooth hurts or an adult tooth has become mobile;
• there are problems with dentures.

If the odor is combined with pain, bleeding gums, or tooth mobility, this is a reason to see a dentist.

Unpleasant breath odor by itself is not a reason to call an ambulance. Calling 103 or 112 is necessary when there is a threat to life — for example, signs of stroke or heart attack, severe injury.

This material is for reference: it explains possible causes but does not replace a doctor's consultation — the final decision on diagnosis and management remains with you and your dentist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer