Patient's Guide to Spirometry

Spirometry is a simple, quick, and painless test used to determine lung function.

In general, spirometry measures how much and how fast you can exhale.

Why do I need a spirometry test?Patients-Guide icon

If you are experiencing symptoms such as hoarseness, shortness of breath, coughing, wheezing, or chest tightness, or have a history of smoking, spirometry will help your healthcare professional diagnose a respiratory condition and possibly prescribe a treatment plan to help you breathe easier.

If you have a respiratory condition such as asthma, chronic bronchitis, emphysema or chronic obstructive pulmonary disease (COPD), regularly scheduled spirometry tests can be used to assess and manage these conditions. If you use respiratory medications, spirometry may also help your healthcare professional determine how well they are working and if a change in medication may be necessary.

How do I take the test?

Spirometry is effort-dependent, that means the results are dependent on you providing the best effort possible. Your healthcare professional will help coach you to be certain you give the best test that you can. To start, you will first inhale as much as you possibly can, then place your mouth on the mouthpiece of the spirometer and exhale as fast and long as you possibly can. Do not stop exhaling until you are told to, even if you feel like your lungs are empty. Typically, your healthcare provider will ask you to perform more than one attempt, just to make sure they get your best effort. Your healthcare professional may also have you take medication during testing. This allows them to determine how well your lungs work with and without medication.

What do the results mean?

Spirometers compare your results to what is considered normal for somebody your age, height, sex, and race. Your results are expressed as a percent of normal. In general, results that are less than 80% of normal usually indicate some respiratory condition such as asthma, emphysema, or chronic bronchitis. However your physician will assist in making that decision and will explain the results to you. Also, be sure to tell your doctor if you smoke, have ever smoked, suffer from allergies, or if you have a family history of respiratory problems.

Example of a Spirometry Test report

Sample printout