Medically Reviewed by Poonam Sachdev on March 04, 2024
4 min read

When you’re having trouble breathing, your doctor might order a test called spirometry. Spirometry is a very common test to see how well your lungs work. Spirometry measures three things:

  1. How much air you can breathe in (inhale)
  2. How much air you can breathe out (exhale)
  3. How fast you can exhale the air from your lungs

Your doctor will look at your test results to figure out what may be making it hard to breathe. Common causes include:

You don’t need to do anything to prepare for spirometry, though there are a few things to keep in mind:

  • Don’t eat a big meal right before the test.
  • Ask your doctor if there are medications you should not take the day of the test.
  • Wear comfortable clothes.

The test itself takes about 15 minutes. It’s done in your doctor’s office, and afterward, you can go about your day as normal.

Spirometry test cost

This test costs around $60. This is the self-pay price; check with your insurance provider to see if they cover the cost of spirometry.



You’ll sit in a chair and have a clip placed on your nose to keep your nostrils closed. Then, you’ll take a deep breath and exhale as quickly and hard as you can for several seconds into a tube.

You’ll need to wrap your lips tightly around the tube so all your air goes into it. The tube connects to a machine called a spirometer. It records how much air you breathe out from your lungs and the speed at which you exhale. Usually, the test is given three times to make sure the results are the same every time. If there are too many differences between the three test results, you may need to take the test again. Your doctor will use the highest value from the three results.

All this information helps the doctor figure out what’s causing your breathing problems.

Spirometry is a painless test. Most people have no problems with it. Depending on your health, the deep breathing might make you feel a little tired or lightheaded.

If you have heart disease or have had surgery recently, check with your doctor to make sure spirometry won’t be a problem for you.

You might hear your doctor or a technician refer to two key measurements in spirometry. They are:

  • Forced vital capacity (FVC). This measures the amount of air you can breathe in and out.
  • Forced expiratory volume (FEV-1). This measures how much air you can exhale from your lungs in 1 second.

A doctor will look at your age, height, and gender to figure out whether your results are in the normal range. Numbers outside this range can suggest a lung problem.

Your doctor should get a report within a few days and talk it over with you.

If the doctor thinks your airways are blocked, they may give you a medication that opens them up. It’s called a bronchodilator. After several minutes, you may take the spirometry test again to see whether the bronchodilator made a difference.

A low FEV-1 score suggests you have an obstructive airway disease such as COPD. This means your lungs can fill with air normally, but your airways are too narrow to exhale as much as they should.

If your lungs can’t fill enough, you have a restrictive lung disease.

There are several types of these conditions, but one of the most common is pulmonary fibrosis. If you have this disease, some of the tissue in your lungs has become scarred. It won’t expand when you inhale, so you can never get quite enough breath.

Spirometry normal values

Things like your height, weight, age, sex, and racial or ethnic background will help determine the normal range for your spirometry results. In general, here are the ranges your doctor will look for: 

  • FEV-1: 80% to 120%
  • FVC: 80% to 120%

This is one of the most important tests for a doctor to diagnose lung disease.

If you’re having any breathing problems, talk about spirometry with your doctor. If there's a chance you might have COPD, asthma, or some other lung condition, this test is a good first step toward getting a diagnosis.

Spirometry is also helpful in testing how well a bronchodilator or other treatment is working. You may have had spirometry testing when you were first diagnosed with asthma. A test after you’ve been taking asthma medications for a while can let you and your doctor know whether you’re on the right treatment track.

If your spirometry results are abnormal, this could be a sign of a lung problem. But keep in mind that sometimes test results can show up as abnormal even when your lungs are fine. The test results will show if you need an inhaler or other medicine for better lung health. You may need to repeat the spirometry in the future to track how well your lungs are working.

Spirometry is a common test used to find out how well your lungs are working by measuring how much air you can breathe in and out, as well as how fast you can do it. It helps diagnose conditions like asthma, COPD, cystic fibrosis, and pulmonary fibrosis. Spirometry is also crucial for figuring out how well treatment is working, especially for conditions like COPD and asthma. If you have breathing problems, discussing spirometry with your doctor is important for proper diagnosis and treatment.