ademgassen

Ademgassen are the gases contained in exhaled breath. They originate from the airways and the lungs and reflect the body's metabolic processes as well as the environment. The bulk of ademgassen is the same as atmospheric air: nitrogen and oxygen, with smaller amounts of carbon dioxide and water vapor. In a typical adult at rest, exhaled breath contains roughly 74–78% nitrogen, 12–18% oxygen, around 4–5% carbon dioxide, and humidity levels high enough that water vapor constitutes several percent of the volume. The CO2 fraction in exhaled air is higher than in inhaled air, due to metabolic production and alveolar gas exchange. End-tidal CO2, the CO2 concentration at the end of exhalation, is used clinically to assess ventilation efficiency.

In addition to these major components, ademgassen include trace gases such as acetone, isoprene, ammonia, methane, and nitric oxide. Many of these volatile organic compounds originate from metabolism or gut and airway microbiota, and others from environmental exposure. The composition of ademgassen is influenced by activity level, health status, smoking, diet, and ambient conditions.

Measurement of ademgassen is central to techniques such as capnography and gas chromatography–mass spectrometry or infrared spectroscopy for breath analysis. Breath analysis is explored for noninvasive diagnostics and monitoring of diseases including asthma, diabetes, infections, and cancer. Related topics include breath analysis, capnography, volatile organic compounds, and spirometry.