Lung tests and cancer treatment

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A lung test, or pulmonary function test, is used to measure how well you lungs are working. Learn why you may need a pulmonary function test and what to expect during the test.

Key points

  • A pulmonary function test measures how well your lungs are working to see if chemotherapy or radiation has affected them.
  • There are different tests that you might need to do including breathing into a spirometer, doing a test to measure how well air moves from your lungs to your blood, a test to measure how much air your lungs can hold, or an exercise test.
  • Pulmonary tests do not hurt, but they may make you feel dizzy.

What is a pulmonary function test?

Pulmonary function tests (PFTs) measure how well your lungs are working. The test might also be called spirometry (say: speh-ROM-et-ree).

Why do I need a pulmonary function test?

You may have pulmonary function tests before, during or after your treatment. Some types of cancer and treatments such as chemotherapy or radiation to your chest can affect how well your lungs work. Your health-care team can compare the tests to keep track of any changes.

How are pulmonary function tests done?

A few different tests are used to check your lungs. You might do all of them or a few of them.

  • You might need to breathe into a tube attached to a machine called a spirometer (say: speh-ROM-et-er). This machine will measure how much and how fast air moves in and out of your lungs. You may be asked to breathe normally or you may be asked to take deep breaths.
  • You might need to breathe a small and safe amount of gas called carbon monoxide to measure how well air moves from your lungs into your blood.
  • You might sit in a special see-through box that looks like a phone booth. When you breathe inside the box, special sensors measure how much air your lungs can hold.
  • You might do an exercise test on a treadmill or exercise bike that tests how well your lungs work when you are exercising.

These tests do not hurt, but you might feel a bit dizzy from taking many deep breaths. If you need to take a break, just tell the person who is doing the test.

Last updated: September 3rd 2019