Small airway disease? Desperate to know more. Any advice out here?

I have recently been diagnosed with high blood pressure and my doctor says I have Small Airway Disease.I'm on permanent calcium channel blockers and diuretics but I can't find any info on SAD except for horses(which I'm not) or references to COPD, which she says it is NOT. Can anyone help me? I can't seem to get any info from the doctors and I'm getting terribly frustrated. I'm supposed to be on low sodium diet but no one can tell me how much sodium is low. What do I do? I suppose I could just lay down and die but I think that's a little extreme!