Asthma and Exhaled Nitric Oxide (eNO)
A Simple, New Breath Test to Help Manage Your Asthma
Asthma is characterized by airway
When airways get inflamed, the inner walls of the airway swell,
so there is less space for smooth flow of air. Inflammation of
the airways leads to symptoms such as shortness of breath,
wheezing and coughing.
The primary focus of asthma treatment is to reduce
inflammation. Unfortunately, current methods of testing lung
function do not measure inflammation. Therefore, your
physician has to correlate symptoms to disease severity when
prescribing or adjusting your medication.
Regular monitoring of eNO provides a more complete
picture of your asthma
Adding eNO tests to other standard clinical
measures gives your physician a better
picture of your airway inflammation. This
can help improve asthma control. By
regularly monitoring your eNO levels,
your physician can treat your asthma
Exhaled nitric oxide (eNO) provides a new way to
Inflamed airways produce nitric oxide which becomes part of your breath.
Exhaled nitric oxide has been studied well over the last 10 years. These
studies have shown a strong relation between eNO and airway inflammation.
Exhaled nitric oxide (eNO) increases as inflammation increases, and it
decreases as inflammation decreases.
Simple breath tests are now available to measure your eNO level. You simply
breathe out steadily into a breath tube that is connected to the test device.
The test itself takes just about 10 seconds. The results are available within
Level of Exhaled Nitric Oxide
Managing asthma is a breath away™
Patient has high
over time after
treatment is adjusted
Illustration of therapy showing
a reduction in inflammation by precise
adjustment of medication
© 2008, Apieron, Inc. ML00021.B
By courtesy of Encyclopaedia Britannica, Inc.,
copyright 2001; used with permis