Breathing and lung function tests

Tests to measure your breathing

What are breathing tests?

Breathing tests measure how well your lungs are working. These tests are used to find the cause of problems such as feeling out of breath. They are sometimes called lung function tests.

Breathing tests measure things like:

  • how much air you can take into your lungs
  • how quickly you can blow air out of your lungs
  • how well your lungs can take up oxygen
  • the strength of your breathing muscles

Your results are compared to what would be expected in healthy people of your age, height, sex and ethnicity.

Your body mass index or BMI

Your health care professional may also weigh you to calculate your body mass index (BMI). This is a way of measuring whether you’re a healthy weight for your height.

Being overweight or underweight can affect your breathing, lung function and general health. Being overweight can cause breathlessness.

Your health care professional will also compare your results with any earlier test results, to track your progress.

Tests include:

We use your comments to improve our information. We cannot reply to comments left on this form. If you have health concerns or need clinical advice, call our helpline on 03000 030 555 between 9am and 5pm on a weekday or email them.

Download this information (576KB, PDF)

Last medically reviewed: January 2020. Due for review: January 2023

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.