Asthma and Exhaled Nitric Oxide (eNO) A Simple, New Breath Test to Help Manage Your Asthma Asthma is characterized by airway inflammation 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 more precisely. Exhaled nitric oxide (eNO) provides a new way to measure inflammation 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 one minute. As airway inflammation increases, eNO increases. Level of Exhaled Nitric Oxide low high higher Managing asthma is a breath away™ eNO Time Patient has high inflammation Inflammation drops 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 permission