Overview
A lung function test is a non-invasive way to examine how well your lungs are working. These tests measure how much air you can breathe in and out, how well oxygen moves into your bloodstream, and how your lungs respond to certain medications. You may be referred for a lung function test because of the respiratory symptoms you’re experiencing, for ongoing monitoring, or to assess your lung health before surgery. The tests are straightforward, usually quick, and entirely painless.
What are the Types of Lung Function Tests
There are several types of lung function tests (also known as pulmonary function tests or PFTs), each designed to measure different aspects of how your lungs perform.
- Spirometry: This is one of the most commonly used tests. It measures how much air you can force out in one second (FEV1) and the total volume of exhaled air (FVC) after a full breath in. It helps determine if there are any limitations to airflow.
- Gas transfer testing: Also known as DLCO, this test looks at how effectively oxygen passes from your lungs into your blood. This test can help assess how well gases move across the lung surface.
- FeNO testing: This test measures the nitric oxide level in your breath. It can indicate inflammation in your airways and may help guide the management of certain conditions.
- Reversibility testing: This test involves taking spirometry readings before and after using a bronchodilator (inhaler). The results show how your lungs respond to medication and whether there is an improvement in your breathing.
Some additional tests, such as lung volume (body plethysmography) and cardiopulmonary exercise testing (CPET), may be used, but routine lung function tests typically only involve the above types.
What Happens During a Lung Function Test?
What happens during your lung function test will depend on which specific tests are needed. In most cases, you can expect the following:
- You will be seated and fitted with a soft nose clip so that all your breathing is done through your mouth.
- A mouthpiece connected to the testing equipment will measure your breathing.
- You will be asked to follow simple instructions such as breathing in deeply, fully, or blowing out quickly and forcefully.
- You may be asked to repeat some of the tests three times to get an accurate average.
- During gas transfer testing, there will be a short rest between measurements to allow your breathing to return to normal gas levels.
- If your appointment includes reversibility testing, you may be given an inhaler and asked to wait roughly 15 minutes before repeating the test.
How Long Does a Lung Function Test Take?
A typical lung function test appointment lasts between 30 and 60 minutes, depending on the number and type of tests performed. Some tests need to be repeated to get a reliable average. Others, such as reversibility testing, involve additional steps like inhaler use and short waiting periods before retesting. Your specialist will explain how long your appointment will likely take and what it will involve.
Why Would You Need Lung Function Tests
There are several reasons why you might be referred for lung function tests. These include investigating symptoms, monitoring an existing respiratory condition, or preparing for surgery. Some symptoms that would call for lung function tests include:
- Chest pain or tightness
- Shortness of breath
- Wheeze
- Coughing, especially when it produces phlegm or mucus
- Difficulty breathing or taking a deep breath.
Testing can help identify patterns in how your lungs work; it allows your doctor to understand the cause of your symptoms, assess the progress of a known condition, or confirm whether current treatment is working effectively. In some cases, testing may be used to help plan surgery by giving a clearer picture of your lung capacity and overall respiratory health.
How To Prepare For a Lung Function Test?
Before your appointment, you will receive specific instructions on how to prepare for your appointment to help get the most accurate results. These instructions may include wearing loose, comfortable clothing that won’t restrict your breathing and avoiding large meals, strenuous exercise, and caffeine for at least 30 minutes before your appointment.
In some cases, you may need to avoid certain medications (such as bronchodilators) temporarily.
Why Go With Mid Ulster Clinic For Your Private Lung Function Tests?
If you’ve been referred for a lung function test, either by one of our consultants or by your own GP, Mid Ulster Clinic offers:
- Faster access to appointments and test results
- Expert-led assessments and personalised care
- A calm, welcoming setting designed with your comfort in mind
- Shorter waiting times compared to the NHS.
These tests are offered on a referral-only basis and must be requested by a doctor. If your GP or specialist has recommended a private lung function test, they can refer you directly to us for testing. Book your appointment today.
- Medically Reviewed
