Tests to check your lungs

What are tests to check my lungs?

You may have different tests to check how well your lungs are working. They are sometimes called pulmonary function tests or PFTs.

Why do I need to have these tests?

Lung problems, such as scarring from previous chest infections or problems caused by some cancer treatments, can affect how well your lungs work. Treatments that can affect the lungs include some chemotherapy drugs, radiotherapy or surgery to the chest.

You might have lung function tests to check your lungs before, during and after treatment.

What happens?

Before the tests

The hospital sends you information about the tests so you know what to expect. They will tell you if there is anything you need to do to prepare for the tests. For example, it is important not to exercise, eat a large meal, smoke or drink alcohol right before the test. These things could affect the results.

During the tests

The person doing the tests (technician) asks you to breathe in and out through a mouthpiece that is connected to a machine. You may have different tests to check your lungs, for example:

  • breathing out quickly to see how fast you can blow air out of your lungs
  • sitting in a see-through booth and having different breathing tests that check how much air your lungs can hold
  • breathing in and out a harmless gas to measure how well oxygen moves from your lungs to your blood
  • exercising on a treadmill to check how well your lungs work while exercising.

The tests are not painful. They can take about 30 minutes in total. Some people feel out of breath or a bit dizzy after doing the breathing in and out exercises. But you will be given time to rest in between the tests. There will be someone with you all the time, so if you start to feel dizzy, let them know.

After the tests

You can usually go straight home afterwards. The technician will tell you when you will get your results. Waiting for test results can be a worrying time. Talking to your family and friends about how you feel can help. You can also speak to your doctor or nurse if you have any problems, or if you need more support.