Stage 1 mild FEV1> 80
Stage 2 moderate FEV1> 50
Stage 3 severe FEV1 > 30
Stage 4 very severe FEV1< 30

Staging is really designed for docs, especially those who aren't pulmonologists to help them figure out a good treatment plan and appropriate meds. It's not very useful for patients because people tend to let it be predictive. We COPDers are way more than our stage or our FEV1 numbers. What counts is what you can do and how good you feel doing it, not what your numbers say you are.

Yes, I get back pain daily. More in the afternoons and early evening. Use CBD OIL and it helps take the edge off

Cheers Jean