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Spirometry

Reviewed by: Amy W. Anzilotti, MD
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What Is Spirometry?

Spirometry (spy-ROM-eh-tree) is a test that measures:

  • how much air a person's lungs can hold
  • the speed of inhalations (breathing in) and exhalations (breathing out)

It's a quick test that usually takes 5–30 minutes.

What's a Spirometer?

Spirometry is done with a tool called a spirometer.

The spirometer (spy-ROM-eh-tur) has:

  1. a mouthpiece
  2. a tube that connects to a device or computer that checks and records results

Why Is Spirometry Done?

Health care providers use spirometry to check how well the lungs are working. It's used to:

  • diagnose and check diseases that affect the lungs, such as asthma and cystic fibrosis
  • find the cause of shortness of breath, coughing, or wheezing
  • check lung function before surgery

How Should We Prepare for Spirometry?

The health care provider will go over how to prepare your child for spirometry. They can also talk with your child about the test and show them how to practice for it.

Ask if your child should:

  • avoid any drinks (such as carbonated drinks like soda) or foods
  • stop any regular medicines (including inhalers). Tell the health care provider about all medicines your child takes, even those you can buy without a prescription (over the counter).

Your child should wear loose, comfortable clothing for the test. Before the test, be sure no one smokes or vapes near your child.

What Happens During Spirometry?

Kids may sit or stand during spirometry.

For the test:

  • A soft nose clip may be put on your child’s nose to prevent air from coming out of the nose.
  • Your child will take a very deep breath, then place a mouthpiece in their mouth and seal their lips around it.
  • Your child then breathes out as hard as possible for as long as possible.

The test is done several times.

The health care provider may give your child a bronchodilator (an inhaled medicine that opens the airways) before and after the spirometry. This shows whether the medicine makes the lungs work better.

When Are the Results Ready?

The results are recorded while the test is being done. Your doctor will review the results and explain what they mean.

Are There Any Risks From Spirometry?

Spirometry is a safe test with little risk. Some kids may feel a little short of breath or dizzy for a few moments after the test. Very rarely, spirometry can cause breathing problems. These are easily treated with an inhaled bronchodilator to open the airways.

This test shouldn't be done on kids who have chest pain, a recent history of surgery, or serious heart disease.

What If I Have Questions?

If you have questions or concerns about spirometry, speak with your doctor or the person giving the test.

Reviewed by: Amy W. Anzilotti, MD
Date reviewed: October 2022