COPD Stages: How Are They Helpful?
How is COPD Diagnosed?
Before we begin, it may be helpful to read my post, “What is a Pulmonary Function Test (PFT)?” So, click on over if you need to. We’ll wait here for you to get back.
According to the updated, 2018, GOLD COPD Guidelines, COPD can be diagnosed based on history.1 Are you feeling COPD symptoms? Do you have a chronic cough? Is it productive? Do you feel short of breath, even if it’s only sometimes? Do you have a history of exposure to noxious chemicals? Did your work expose you to fumes, gases, or airway irritants? Did you smoke? Were you exposed to second-hand smoke? So, you may be diagnosed based on this information alone. So, that’s true for many people with COPD.1-3
But, also according to the same Guidelines, a PFT is essential to getting an official COPD diagnosis. It can help rule out other disorders (differential diagnosis) and rule in COPD.1
How can a PFT diagnose COPD?
As part of this test, you will do a Forced Vital Capacity (FVC). This is when you take in a breath as deep as you can. Then you exhale until you can't get any more air out. Using your FVC, a computer will calculate your FEV1. This is the value we are looking for.
So, what is FEV1? It is the amount of air you exhaled during the first 1 second of your FVC. Normal is 80%. Most people should be able to exhale 80% of the air in their lungs in 1 second. Anything less than 80% means you have "airflow limitation." This means you have something obstructing the flow of exhaled air. This can make you feel short of breath.
Now, after you do this FVC your FEV1 will be determined. Say your FEV1 is 50%. This means you are only able to get 40% of your air out in the first 1 second of your FVC. To diagnose COPD, you have to get a bronchodilator breathing treatment. Usually, albuterol is used. You then wait for 10-15 minutes and do a second PFT. You blow another FVC. A new FEV1 is determined.
If your FEV1 improves by 12% or more after the bronchodilator, you have asthma.4 This is because asthma is reversible. Asthma attacks improve with treatment. If it doesn't improve or improves less than 12%, chances are you have COPD. This is how a diagnosis of COPD is confirmed.
After you do a PFT, you will be given a breathing treatment with albuterol. You will then wait about 15 or so minutes for the medicine to fully work. After this rest period, you will do another PFT test. A new FEV1 will be determined.
Once a diagnosis of COPD is made, this post-bronchodilator FEV1 is used to determine what stage of COPD you are in.1
What are the stages of COPD?
Your Post-Bronchodilator FEV1 is used to determine your stage. Your doctor uses this to determine if you are in stage 1, 2, 3, or 4.1,5-6
- Mild. FEV1 is 80% or greater
- Moderate. FEV1 is 50% to 80%
- Severe. FEV1 is 30% -50%
- Very Severe. FEV1 is less than 30%
So, if your post-bronchodilator FEV1 is 40%, you can be diagnosed with Severe COPD.
How Can Knowing Your Stage Be Helpful?
If you are diagnosed with a disease, you’ll want your doctor to be honest with you. You will want to know how severe it is. You may not want to hear this. It’s not easy for patients to hear. It’s probably not easy for doctor’s to say either. But, it’s very important. It’s important because the progression of COPD can be slowed. This is true no matter where you are at. It’s true no matter what stage you are in.
So, your doctor says you are in stages 1 or 2. You can think of this as good news, in a way. You were diagnosed early on in the disease process. Damage done cannot be reversed. But, the damage is mild or moderate. There is lots of lung function yet to be preserved. There is damage that can be prevented. But, you must take actions right now.
So, your doctor says you are in stages 3 or 4. These are often considered the later stages of COPD. Sometimes they’re called the advanced stages. Unfortunately, we in healthcare often refer to stage 4 as “End Stage.” That dirty, rotten word no one wants to hear. So, we try to dial it back and refer to it as "Very Severe COPD.”
Here’s the thing though. You want to know where you stand. A doctor knows the progression of COPD can be slowed. Doctors know, that no matter when you quit smoking (for example), your life can be prolonged. You can add years to your life. So, you’ll want your doctor to be honest with you.
Your doctor might say, “Look! You have Severe COPD!” What it means is you need to take it seriously right now. You cannot delay anymore if that’s what you’ve been doing. That's why staging, I think, is important. That’s why a doctor might say, “You have end-stage COPD!” It’s so you take it seriously.
What to make of this?
That all said, now you know why it's so important to do a PFT. It's a test that is performed to give you that official diagnosis of COPD. It's also useful for determining what stage of COPD you are in. This helps your doctor determine how severe it is. And this can be used to determine where you stand.
Know that no matter where you are at, actions you take now can slow the progression and add quality years to your life.
Has your COPD progressed? In what ways? Share with the community!
Editors Note: This article has been updated for accuracy.
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