Explore This Testing Lab

About Our Program

Purpose of Pulmonary Function Testing

Pulmonary function tests measure the size of the lungs, how well the lungs take in and exhale air, and how efficiently the lungs transfer oxygen and carbon dioxide in and out of the blood. We compare the results of these tests with the values that are expected based on your age, ethnic origin, gender and height.

Pulmonary Function Tests

The following tests are generally performed while you are at rest. In most cases, you will wear a nose clip and mouthpiece while breathing into a machine that captures relevant information.

  • Spirometry determines the maximum flows generated while breathing forcefully in and out. This test also assesses your response to inhaled medications that might improve lung performance
  • Methacholine challenge testing, also known as bronchoprovocation test, evaluates the lungs’ reaction to things in the environment, and can be used to help diagnose asthma. The test involves undergoing multiple spirometry tests after breathing in the drug methacholine, which causes narrowing of the airways, similar to those seen in asthma
  • Lung volume measures the size of the lungs
  • Single breath diffusing capacity analyzes how efficiently the lungs can transfer oxygen from the air into the blood; also known as "diffusion capacity for carbon monoxide"
  • Respiratory muscle forces testing gauges the strength of the muscles used for breathing and for coughing
  • Arterial blood gas analysis measures the amounts of oxygen and carbon dioxide in the blood as well as the acidity (pH) of the blood
  • FeNO (fractional exhaled nitric oxide) measures the amount of nitric oxide in the exhaled breath and is used to assess possible causes of cough, wheezing and shortness of breath, and to evaluate the effectiveness of treatments for asthma. High levels of nitric oxide can be a sign of inflammation (e.g. irritation or swelling) in the airways