The official blog of the Lung Institute.
If you have a chronic lung disease, then you’ve likely had a pulmonary function test. Pulmonary function tests give your doctor valuable information about how well your lungs are working. Having this information helps your doctor monitor your condition and develop the best treatment plan for you. Here are the important details you need to know about having a pulmonary function test.
What is a Pulmonary Function Test?
Simply, a pulmonary function test is a way to measure lung function. There are several types of pulmonary function tests. The most common lung function tests include spirometry, gas diffusion and lung plethysmography.
Types of Common Lung Function Tests
- Lung Plethysmography
- Gas Diffusion Tests
- 6-Minute Walk Tests
- Cardiopulmonary Exercise Tests
- Pulse Oximetry
What does a Pulmonary Function Test Measure?
A pulmonary function test can measure lung size, air flow, lung volume, lung diffusion and more. Specifically, the pulmonary function test called spirometry measures how much air you inhale, how much air you exhale and how quickly you can exhale it.
The pulmonary function test called lung plethysmography measures the amount of air in your lungs after taking a deep breath and the amount of air that remains in your lungs after exhaling as much as you can.
Key Terms: Measurements Gained from a Pulmonary Function Test
- Forced Vital Capacity (FVC)—Total amount of air you can exhale after taking the deepest breath you can.
- Forced Expiratory Volume in One Second (FEV1)—Amount of air you can forcefully exhale during the first second of the FVC test.
- Total Lung Capacity (TLC)—Total amount of air in the lungs after you take a deep breath.
- Forced Expiratory Volume (FEV)—Amount of air forcefully exhaled during the first, second and third seconds of the FVC test.
- Peak Expiratory Flow Rate (PEFR)—Measures how fast you can exhale. Estimated values depend on gender, ethnicity, height, weight and age.
- Forced Expiratory Flow (FEF)—Flow or volume in the middle of an exhalation.
- Functional Residual Capacity (FRC)—Amount of air that remains in the lungs after you breathe normally.
- Maximum Voluntary Ventilation (MVV)—Amount of air you can inhale and exhale in one minute.
- Minute Volume (MV)—Amount of air exhaled per minute.
- Vital Capacity (VC)—Total volume of air you can breathe out after inhaling as much as you can.
- Tidal Volume (VT)—Amount of air inhaled or exhaled during normal breathing
Who Needs to Have a Pulmonary Function Test?
There are a few reasons why someone might need a pulmonary function test. For example, your doctor may recommend a pulmonary function test if you have certain health problems such as allergies, respiratory infections and chronic lung disease. Often, doctors use pulmonary function tests to help them diagnose the type of chronic lung disease, to develop a treatment plan and to monitor your condition over time.
Are There Any Risks Involved with a Pulmonary Function Test?
Pulmonary function tests are not invasive, so they are generally considered safe for most people. It’s important to follow the technician’s and your doctor’s instructions before, during and after your pulmonary function test.
While unlikely to occur, possible risks associated with pulmonary function tests may include:
- Shortness of breath
In some instances, certain people may not be able to have a pulmonary function test. Tell your doctor if you have had recent eye surgery, recent belly or chest surgery, chest pain, recent heart attack, a bulging blood vessel (aneurysm), active tuberculosis or a respiratory infection.
What Can I Do to Prepare for a Pulmonary Function Test?
Ask your doctor to explain the type of pulmonary function test you will have, and discuss your questions or concerns with your doctor. Your doctor may tell you not to take certain medications prior to the test. Before the test, your doctor may also advise that you:
- Stop smoking
- Not eat a heavy meal
- Wear loose fitting clothing
- Stop taking certain medications for a little while (as instructed by your doctor)
During the test, you will be given specific instructions to follow. Always follow the directions as best you can and ask questions if something is unclear. You may be asked to repeat the test after taking a bronchodilator. You may feel tired after the test, and you will be given time to rest. After the pulmonary function test is completed, your doctor will go over the results with you during an office visit.
What Are Your Next Steps?
If your doctor has ordered a pulmonary function test, make sure that you understand the test and ask questions if anything is unclear to you. Follow your doctor’s instructions. Over time, your doctor may recommend having another pulmonary function test, so your doctor can monitor how your treatment plan and lungs are doing. Chronic lung disease treatments include inhalers, oral corticosteroids, oxygen therapy, pulmonary rehabilitation and cellular therapy. Sometimes, a combination of these treatment options is used. If you or a loved one has COPD, emphysema, pulmonary fibrosis or another chronic lung disease and would like to learn more about cellular therapy options, contact us at (800) 729-3065.