An exhaled nitric oxide test is one of those many tests which are used to check for asthma. In a nitric oxide test, a deep breath is inhaled into the lungs and exhaled into the mouthpiece attached to a machine that measures the level of nitric oxide in your breath. Nitric oxide is one of those gases that cause inflammation in the airway which is a possible symptom of asthma.

The main advantage of performing the nitric oxide test is that you or your doctor can easily adjust the dose of steroid when there is a lack of good tool for establishing the best dose of steroids since for some it would be too low, at the same time it would be very high for others.

It would not be wrong to say that nitric oxide measurement is the step forwarding in assessing asthma. Well doctors now have a new tool which can help them assess the severity of asthma, which will certainly help them better predict your need for inhaled corticosteroid medication. Well one of the reasons for  the underuse of nitric oxide test is the current high cost of machine although companies are working on making portable, less costly machines that would be available in coming 3 years.