This pulmonary function test for asthma and other lung problems is a simple breathing test that measures how much air you can blow out of your lungs and how quickly. It is often used to determine the amount of airway obstruction you have. Spirometry can be done before and after you inhale a short-acting medication called a bronchodilator, such as albuterol. The bronchodilator causes your airways to expand, allowing for air to pass through freely. This test might also be done at future doctor visits to check your progress and to help your doctor determine if and how to adjust your treatment plan.

WebMD. (2009, June 21). Retrieved from http://www.webmd.com/asthma/guide/lung-function-tests-asthma