What you really want to know is what factors led your current doc to his diagnosis and determination of the "stage" of your disease. The other thing you need to know is which "staging" protocol is he using, because they are different and sometimes overlapping. The Gold and the COPD Foundation protocols are generally the same, but GOLD has four stages and the Foundation only three. The factors in determining which stage you're at include objective data and non-objective data and some judgments are required. The most objective piece of data is the FEV1. Both staging protocols are clear about those. The next thing that's looked at is number of exacerbations and here's where it can get murky. Technically, an exacerbation is a worsening of your symptoms requiring medical intervention to get rid of. HOWEVER, there's a big difference between an exacerbation that requires an antibiotic and no "down time" on the part of the patient and one that puts the patient in the hospital and out of commission for several weeks to a month and requires a very long recovery time. The last thing is what the patient is capable of doing; what sort of life does the patient lead? And that depends on two people's judgment: the patient's and the doc's. As you can see, this isn't simple, and it's not exactly objective. There are two other things that are important here. The first is that the whole staging thing was designed to help docs who aren't pulmonologists determine which meds and treatments are appropriate for patients at which stages of the disease. It was never designed for patients. The second thing is that the people who make the determinations regarding disability look only at FEV1; they don't look at staging, so your doc's staging of you really doesn't make any difference. Go to the Social Security Disability website and look up the criteria for disability and COPD.

When I was first diagnosed in 2010 I was in stage 3, hardly felt anything, wasn’t hardly taking any medication. This year I am in stage 4, take medication everyday, I feel a big difference from stage 3 to stage 4.

I should have added, yes it's perfectly possible to go from one stage to another, up or down. A lot of that depends on how well you do the spirometry or Pulmonary Function Test. Results can be worse if you're not feeling well or are sick when you do it or if the technician doing the test isn't experienced. A good coach can make a huge difference. A one point difference can put you in one category or another. You need to find out what your FEV1 was on each of those tests to get a feel for what happened. You should always ask for copies of test results so you have them for reference. Last bit of advice I have is this: your numbers don't define you; what you can do and how comfortable you are doing it is what really defines you. So do everything you can to make yourself as fit and strong as possible and look for ways to do things instead of listing all the reasons why you can't. I have friends with COPD who run marathons and climb 14,000 foot peaks in Colorado; I travel a lot, usually by air and usually at least twice a month, using O2. You can do just about anything you want to do; you just need to figure out how.

I was alway told by my pulmonologist that COPD was my curable., and that you could only slow down it’s progress. I hope your PFT was accurate

I know my primary doc told me in January that I have only 55% lung capacity. However he tends to be an alarmist I think. I will be seeing pulmonologist tomorrow at 11:30 to check on progress. I have been in quarantine for 3 months for the COVID but I do go our to get groceries.