//The composition of halitosis (bad breath)
The composition of halitosis (bad breath) 2018-03-23T12:51:15+00:00

Malodour compounds

Our perception of smell starts with chemical substances found in the air, which stimulate the receptor cells of the olfactory bulb. These substances, with different compositions and physicochemical structures, have two properties in common: volatility (the tendency of a liquid to evaporate) and solubility. However, no chemical equation exists for determining whether a substance will trigger a pleasant or unpleasant odour.

In the past, doctors believed that changes in the breath could be symptomatic of certain illness and attempted to identify them according to the unique odour of the patient. Modern breath analysis began in the 1970s, when Linus Pauling (Nobel Prize in chemistry) detected, but did not identify, more than 200 volatile organic compounds (VOCs) which were able to be separated by using gas chromatography techniques. For the first time, what we commonly consider “normal human breath” was shown to be gas with a complex composition.

The 3,000 compounds found in human breath.

Nowadays, we have available modern analytical instruments for identifying and measuring the different compounds exhaled by the human body. However, the use of these instruments is not widespread. The most well-known tests are those designed to detect a bacterium called Helicobacter pylori; a concentration of ethanol and acetaldehyde (known as alcohol tests); and those used to detect nitric oxide in asthma patients. And, one field which is generating a lot of interest from the scientific community the early diagnosis of lung cancer through the study of these exhaled compounds.

In the last 30 years, a diverse range of compounds has been identified, and it has also been confirmed that samples of exhaled air (coming from the same individual) can contain more than 200 VOCs. Some factors can influence the composition of human breath, such as physical condition, diseases, general state of health, the intake of certain foods and medicines, environmental factors and lifestyle. To date, over 3,000 different compounds have been detected in the breath. It is worth noting that the International Association for Breath Research (IABR) has a continuously updated database that documents all of the volatile substances of human and animal origin that have been discovered in different testing centres around the world.

Volatile compounds

Volatile compounds found in exhaled air can be classified into three main groups.



We talk about halitosis open and accessible way, so that you can understand medical terminology that scientists use.

1. What is halitosis?
2. Physical and social consequences
3. Bad breath through the ages


The Breath Institute has discovered, on the basis of the latest international research, that there are over 80 possible causes of halitosis.

1. The composition of halitosis (bad breath)
2. Causes of halitosis (bad breath)
2.1 Oral causes
2.2 Respiratory causes
2.3 Digestive causes
2.4 Systemic causes, diet and habits
2.5  Neuropsychological causes


We identify the most effective clinical methods when diagnosing precisely the halitosis’ origin, so that you can chose the best treatment.

1. Methods of diagnosis
1.1 Self-perception
1.2 Organoleptic tests
1.3 Breath gas measurement
1.4 Laboratory tests
2. Psychological tests
3. Signs and associated symptoms