The primary sign of halitosis (bad breath) is a foul odor emanating from a person’s mouth upon exhaling or when talking. This odor can have a distinctive smell, depending on its cause. For example, sweet or “fruity” smelling breath may indicate diabetes. Breath that smells like feces may indicate a bowel obstruction, and breath that smells like ammonia or urine may indicate kidney failure.

People with halitosis may or may not be able to detect the unpleasant odor themselves. Anyone who has become accustomed to a certain body odor may no longer notice it or may not view it as unpleasant. In such cases, people with halitosis may discover the condition based upon the reactions of others (e.g., stepping away from a person with halitosis when that person is speaking). In addition, other people may inform a person with halitosis that they have bad breath. 

Additional signs and symptoms may appear with halitosis, which can indicate a dental problem or medical illness. These may include:

• Food particles, plaque or tartar on the teeth
• Tooth decay
• Swollen gums
• Drainage from the mouth
• Open sores inside the mouth
• Dry mouth
• Bad taste in the mouth
• Cold or flu-like symptoms (e.g., sore throat, fever)
• Signs of an underlying medical condition (e.g., heartburn due to acid reflux, vomiting due to a bowel obstruction)

Patients should consult their dentist or physician if their halitosis is accompanied by signs of a tooth or gum condition (e.g., tooth decay, swollen gums), or if halitosis continues despite a proper diet and dental care. A physician should be contacted for halitosis with signs of infection or other medical illness (e.g., diabetes, kidney disease).