Is anyone familiar with this term? I think this might be the label best applied to me. It might be why despite a fairly decent last pft, I still struggle. The problem is it does not respond to most inhalers as they do not go deep enough into lungs. My latest numbers: FVC 4.77 (99%), FEV1 3.17 (84%), FEV1/FVC 66%, FEF 25-75% 1.95 (58%). My FEF being so low might indicate this condition from my research. Any input/advice would be greatly appreciated.