With my doc they could tell I also had asthma b/c of how well I respond to the albuterol during PFTs. You knnow when you get the full test and they make you blow a few times, then give you albuterol to see if you can get higher? My hunch is that if your PFTs don't improve significantly 10 minutes after albuterol, then you might not have asthma or not as bad as others. For me, it helps a ton. I'm also effected by cold weather, perfumes, etc, which apparently points to asthma as well. I don't have allergies.