A dentist or physician can usually identify halitosis (bad breath) by smelling a patient’s breath. An examination of the teeth and gums is usually conducted to identify or rule out an oral cause of the halitosis. If gum disease is suspected to be the cause of a patient’s halitosis, consultation with a periodontist may be recommended.

A physical examination, including feeling the head or neck, may be conducted to identify any signs of infection, which may be causing the halitosis. A medical history may be taken in order to identify other possible causes of the problem. A patient may be asked about when symptoms began, current medications, diet and tobacco use.

Sometimes a potential cause may be identified based on how the breath smells (e.g., a “fruity” smell may indicate diabetes). If a non-oral cause is suspected, patients may be referred for additional testing. These tests may include blood tests, urine tests and x-rays of the chest or sinuses.