A Pulmonary Function Test (PFT), also known as Lung Function Test (LFT) is a group of tests that measure how well your lungs are functioning. These tests help your doctor diagnose and monitor lung diseases, including chronic obstructive pulmonary disease (COPD), asthma, and other respiratory conditions. In this article, we will discuss the basics of PFT, including how it is done, what to expect during the test, and how to interpret the results.
What is a Pulmonary Function Test?
A Pulmonary Function Test is a non-invasive test that measures lung function. The test is usually performed in a special laboratory or clinic, and it typically takes about 30 minutes to complete. During the test, you will be asked to breathe into a device that measures the volume and flow of air that you inhale and exhale.
The test may include several different measurements, including:
- Spirometry: measures the volume of air you can exhale forcefully after taking a deep breath
- Lung volumes: measures the amount of air in your lungs at different points during breathing
- Diffusing capacity: measures how well your lungs transfer oxygen and carbon dioxide into and out of your bloodstream
Why is a Pulmonary Function Test done?
A Pulmonary Function Test is done to evaluate how well your lungs are functioning. It can help diagnose lung conditions such as asthma, COPD, and pulmonary fibrosis. It can also help monitor the progression of these diseases and determine how well treatments are working.
What to expect during a Pulmonary Function Test?
During the test, you will be asked to sit in a chair and breathe into a mouthpiece connected to a machine. You will be instructed to take deep breaths and then blow out as hard and as fast as you can. You may need to repeat this several times to get accurate measurements.
The test is usually painless, but some people may feel lightheaded or dizzy after blowing into the mouthpiece. If you feel uncomfortable or have trouble breathing during the test, let the technician know immediately.
What do the results of a Pulmonary Function Test mean?
The results of a Pulmonary Function Test can help your doctor diagnose and monitor lung conditions. The results are usually reported in a graph or table format, and they include several different measurements.
The most important measurement is the Forced Vital Capacity (FVC), which is the maximum amount of air you can exhale after taking a deep breath. Other measurements include Forced Expiratory Volume in 1 second (FEV1), which is the amount of air you can exhale in the first second of a forced breath, and Total Lung Capacity (TLC), which is the maximum amount of air your lungs can hold.
The normal range for these measurements can vary depending on age, height, gender, and other factors. Here is a table showing the normal ranges for some common measurements:
|Forced Vital Capacity||4.5-5.5 liters|
|Volume in 1 second||80-120% of predicted for age,|
|height, and gender|
|Total Lung Capacity||4-6 liters|
|Peak Expiratory Flow||400-700 liters per minute|
|Pressure||-100 to -150 cm H2O|
|Pressure||100-150 cm H2O|
Is a Pulmonary Function Test painful?
No, a Pulmonary Function Test is usually painless. You may feel lightheaded or dizzy after blowing into the mouthpiece, but this is temporary.
How long does a Pulmonary Function Test take?
A Pulmonary Function Test usually takes about 30 minutes to complete.
What should I do to prepare for a Pulmonary Function Test?
You should avoid smoking or using any inhalers or bronchodilators for several hours before the test. You should also wear comfortable clothing and avoid eating a large meal before the test.
Can anyone get a Pulmonary Function Test?
Generally, anyone who is able to follow the instructions and blow into the mouthpiece can get a Pulmonary Function Test. However, there may be some conditions, such as recent chest surgery or severe respiratory distress, that may make the test unsafe or difficult to perform.
Is a Pulmonary Function Test covered by insurance?
In most cases, a Pulmonary Function Test is covered by insurance. However, you should check with your insurance provider to confirm coverage and any potential out-of-pocket expenses.
Can a Pulmonary Function Test diagnose all lung conditions?
While a Pulmonary Function Test can help diagnose and monitor many lung conditions, it may not be able to detect all types of lung diseases or conditions. Your doctor may recommend additional tests or imaging studies to confirm a diagnosis.