without healthy lungs, there’s no healthy life.
At Allergy and Pulmonary we believe that it’s important to put your health in the hands you trust. Proper testing leads to early and correct diagnosis which results in the best of care when it matters most.
Pulmonary Diagnostic Testing can range from simple spirometry which measures lung capacity and can screen for diseases such as asthma and COPD to full Pulmonary Function Testing which will evaluate a large array of Pulmonary Diseases. Testing can also include Chest X-Rays, CT Scans and PET Scans to better evaluate the chest and lungs and measures of oxygen at rest and during exercise.
types of pulmonary function testing
Pulmonary Function Testing
Pulmonary function tests (PFTs) are non-invasive tests that show how well the lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. This includes how well you’re able to breathe and how effective your lungs are able to bring oxygen to the rest of your body. PFTs are performed in our office.
Methacholine Challenge Testing
Methacholine challenge is a breathing test that evaluates your lung function. It is used to check for asthma in patients who have a cough, shortness of breath, or other breathing problems. Methacholine is a medication that causes your airways to narrow if you have asthma. During the test, you will breathe in small amounts of methacholine and your lung function will be measured. Methacholine Challenge testing is performed on an outpatient basis.
Exercise Pulse Oximetry
Pulse oximetry measurements are performed in our office during walking exercises. Performing these tests allows us to assess for low oxygen levels during activity. Based off the results of the tests, we are able to understand how effectively your heart, lungs and circulatory system work together.
AMERICAN THORACIC SOCIETY – pulmonary function tests
Pulmonary function tests (PFT’s) are breathing tests to find out how well you move air in and out of your lungs and how well oxygen enters your body. The most common PFT’s are spirometry (spy-RAH-me-tree), diffusion studies and body plethysmography (ple-thiz-MA-gra-fee). Sometimes only one test is done, other times all tests will be scheduled, often on the same day.
Take the time to read through the below questions and answers. Educating yourself on Pulmonary function tests will help you understand why they’re so important. Like anything else, catching a health issue in the beginning or very early stages, can be the difference between an easy fix / adjustment or a painstaking battle.
Lung function tests can be used to:
- Compare your lung function with known standards that show how well your lungs should be working.
- Measure the effect of chronic diseases like asthma, chronic obstructive lung disease (COPD), or cystic fibrosis on lung function.
- Identify early changes in lung function that might show a need for a change in treatment.
- Detect narrowing in the airways.
- Decide if a medicine (such as a bronchodilator) could be helpful to use.
- Show whether exposure to substances in your home or workplace have harmed your lungs.
- Determine your ability to tolerate surgery and medical procedures.
To get the most accurate results from your breathing tests:
- Do not smoke for at least 1 hour before the test.
- Do not drink alcohol for at least 4 hours before the test.
- Do not exercise heavily for at least 30 minutes before the test.
- Do not wear tight clothing that makes it difficult for you to take a deep breath.
- Do not eat a large meal within 2 hours before the test.
- Ask your health care provider if there are any medicines that you should not take on the day of your test.
What is spirometry?
Spirometry is one of the most commonly ordered lung function tests. The spirometer measures how much air you can breathe into your lungs and how much air you can quickly blow out of your lungs. This test is done by having you take in a deep breath and then, as fast as you can, blow out all of the air. You will be blowing into a tube connected to a machine (spirometer). To get the “best” test result, the test is repeated three times. You will be given a rest between tests.
The test is often repeated after giving you a breathing medicine (bronchodilator) to find out how much better you might breathe with this type of medicine. It can take practice to be able to do spirometry well. The staff person will work with you to learn how to do the test correctly.
It usually takes 30 minutes to complete this test.
What should I know before doing a spirometry test?
- You may be asked not to take your breathing medicines before this test.
- Instructions will be given on how to do this test. If you do not understand the instructions, ask the staff to repeat them.
- It takes effort to do this test and you may become tired. This is expected.
- If you become light-headed or dizzy during this test, immediately stop blowing and let the staff know.
What are diffusion studies?
Diffusion tests find out how well the oxygen in the air you breathe into your lungs moves from your lungs into your blood. Like spirometry, this test is done by having you breathe into a mouthpiece connected to a machine. You will be asked to empty your lungs by gently breathing out as much air as you can. Then you will breathe in a quick but deep breath, hold your breath for 10 seconds, and then breathe out as instructed. It usually takes about 15 minutes to complete this test.
What should I know before doing a diffusion test?
- Do not smoke and stay away from others who are smoking on the day of the test.
- If you are on oxygen, you will usually be asked to be off oxygen for a few minutes before taking this test.
What is body plethysmography?
Body plethysmography is a test to find out how much air is in your lungs after you take in a deep breath, and how much air is left in your lungs after breathing out as much as you can. No matter how hard you try, you can never get all of the air out of your lungs. Measuring the total amount of air your lungs can hold and the amount of air left in your lungs after you breathe out gives your health care providers information about how well your lungs are working and helps guide them in your treatment. This test requires that you sit in box with large windows (like a telephone booth) that you can see through. You will be asked to wear a nose clip and you will be given instructions on how to breathe through a mouthpiece. If you have difficulty with being in closed spaces (claustrophobia), mention this to your provider ordering the test. This will avoid any misunderstanding and discomfort to you. It usually takes about 15 minutes to complete. Some PFT labs will use other tests instead of plethysmography to measure the total volume of air in your lungs.
What should I know before doing a phlethesmography test?
- Some laboratories will use other tests instead of plethysmography, to measure the total volume of air in your lungs.
- If you are on oxygen, you will usually be asked to be off oxygen during this test.
- Let the staff know if you have difficulty in closed spaces.
What are normal results for lung function tests?
Because everyone’s bodies and lungs are different sizes, normal results differ from person to person. For instance, taller people and males tend to have larger lungs whereas shorter people and females have smaller lungs. A person’s lungs grow until they are in their mid-twenties and then after that, lung function falls slightly every year.
There are standards that your health care provider uses that are based on your height, weight, age, and gender. These numbers are called the predicted values. Your measured values will be compared to these standard values. Your own lung function can be tracked over time to help see if you have had a change.
Authors: Bonnie Fahy, RN, MN; Marianna Sockrider, MD, DrPH; Suzanne Lareau, RN, MS.
Updated: Marianna Sockrider MD, DrPH
Reviewer: Brian Graham MD
Additional Lung Health Information