A spirometry test is not required as a part of every CDL medical exam. But if your doctor has any concerns about your lung function, they may ask you to take one. If you’ve never taken a spirometry test, you might feel concerned about the testing procedure and what it means for you.
In this blog, we will clear the air and explain what you can expect from a spirometry test and how it might impact your ability to pass your DOT physical exam.
What is a Spirometry Test?
Spirometry is a type of non-invasive procedure to test your pulmonary function. Basically, it measures how well your lungs work and how much oxygen you move when you breathe. This is important for drivers because low lung function can lead to shortness of breath, fatigue, and daytime drowsiness and make it unsafe for drivers to operate a motor vehicle.
In a spirometry test, you breathe into a tube, which measures how much and how quickly the air moves through the tube when you exhale.
Who Needs to Take a Spirometry Test?
If you have a history of lung issues or any breathing problems, your doctor will ask you to take a spirometry test. If you report symptoms such as excessive fatigue or snoring, a certified medical examiner may use a spirometry test to determine if a sleep test is warranted. If you have ongoing breathing issues such as asthma or chronic obstructive pulmonary disease (COPD), a doctor can use a spirometry test to evaluate how severe your symptoms are and if treatments are working.
Drivers with a history of smoking or occupational lung exposures (such as diesel exhaust, silica dust, welding fumes, or asbestos) might be asked to take a test to measure their lung capacity and assess any lung damage.
Any condition that limits a driver’s lung capacity can lead to hypoxia (low oxygen levels.) This, in turn, may lead to fatigue, drowsiness, and dizziness. It can make it difficult for a driver to operate a vehicle safely, especially in high-stress conditions. A spirometry test allows your doctor to accurately evaluate your lungs and breathing and make the appropriate treatment recommendations to keep you safe and on the road.
Taking a Spirometry Test
You should wear loose-fitting clothing, avoid tight waistbands or belts, and avoid eating a big meal before taking your spirometry test. This makes it easier to give a good breath sample. You should also avoid smoking, drinking alcohol, or participating in strenuous exercise for 24 hours before your test. If you are using any breathing medications, such as bronchodilators, your doctor might ask you to stop taking them before the test so they can evaluate their effect on your breathing.
When you arrive at the doctor’s office for your test, here is what you can expect:
- The doctor will measure your height and weight.
- You will apply a nose clip to ensure you breathe through your mouth.
- You will breathe directly into the tube as quickly and forcefully as possible for a few seconds.
- You’ll repeat this procedure three times.
- The spirometry creates a graph of your lung function.
Who Should Not Take a Spirometry Test
There are a handful of scenarios where it would be unsafe or unadvisable for you to take a spirometry test. Talk to your doctor, and do not take a test if:
- You have chest pain or have recently had a stroke or heart attack.
- You have had recent abdominal surgery.
- You have recently undergone eye surgery (hard breathing puts pressure on your eye).
- You have a collapsed lung.
- You have an aneurysm.
- You have Tuberculosis.
- You have a respiratory infection, such as pneumonia, a cold, or the flu.
It is not dangerous to take a spirometry test if you are pregnant, bloated, or extremely fatigued, but it might be difficult to give a strong breath. These conditions might affect the accuracy of the test, and you should discuss them with the doctor beforehand.
Getting enough sleep the night before your test and eating a light meal will help you get the most accurate results.
What Does a Spirometry Test Mean for Your DOT Medical Certificate?
Just because a doctor has asked you to take a spirometry test does not mean you cannot pass your DOT medical exam. It is possible to continue driving commercially even with lung or breathing conditions. However, continuing to drive with undiagnosed and untreated breathing issues can put you and others at risk. It is critical that you identify and address any conditions that might be affecting your breathing or lung capacity with a doctor.
If a pulmonologist uses a spirometry test to determine that you have asthma, sleep apnea, COPD, pulmonary fibrosis, or other breathing conditions, they will recommend further testing and treatment to ensure that you are fit for duty.
There is no need to think of a spirometry test as a roadblock to passing your DOT CDL medical exam but rather as a tool to keep you healthy and safe on the road.
Video
Infographic
A spirometry test isn’t mandatory for every CDL medical exam; however, your doctor might request one if they have concerns about your lung function. If you’ve never undergone a spirometry test, it’s natural to feel a bit uneasy about the procedure. Learn more in this infographic.
