Bad breath is a common problem and is estimated to be the 3rd most frequent reason for seeking dental aid, following tooth decay and gum disease. In most cases bad breath is transient, often disappearing following a meal, brushing one's teeth, flossing, and rinsing with an effective mouthwash. Halitosis can also be persistent (chronic bad breath), which is a more serious condition, affecting some 25% of the population in varying degrees. It can negatively affect an individual's personal, social and business relationships, leading to poor self-esteem and increased stress.

Halitosis is usually caused by the metabolic activity of certain types of oral bacteria - in the mouth, the throat and the nasal passages. Those bacteria populations thrive on deposits of food, dead epithelial cells and postnasal drip. During the process proteins are decomposed, to produce unpleasant odors.

Most researchers today agree that the most common origin for bad breath is the posterior dorsum of the tongue (85-90% of halitosis cases), the nose is responsible for 5-7% of the cases, the tonsils for 3-5%, and the other fractions of percents arise from other medical conditions.

Beside the bacteria, there are some contributing factors to bad breath:

• Oral dryness - which may be due to stress, fasting or caused by certain medications and medical conditions.
• Eating certain foods - garlic, onions, meat, fish and cheese are known to contribute to bad breath.
• Postnasal drip – nasal conditions are considered to have a major influence on bad breath. Sinusitis, narrow nasal passages and chronic nasal drip – can all be contributing to oral malodor.
• Obesity – a research we recently published shows an association between this factor and bad breath.
• Smoking – contributes to oral dryness.
• Alcohol consumption – by causing dryness and by being decomposed by the oral bacteria.
• Mouth breathing – at night the mouth is dry and inactive, and the odor is usually worse upon awakening ("morning breath") for that reason. Some people breath mostly through their mouth not just at night but also during the day, which can also contribute to the oral malodor.