Last winter I got a cough that wouldn't clear up. X-rays ruled out anything too nasty, but it was a real drag. Anti-biotics of various sorts, but nothing cleared it.
In the end the doctor decided it was probably asthma, and gave me the right kinds of inhalers, and it cleared up. Except I'll have to be useing them from now on on a regular basis, but that's not a major problem.
The point is, I've never had asthma in my life, and I'd never realsed you could develop it well-on in years. And the doctor hadn't thought of it for some time either, just took it to be an infection (which it was as well, but secondary, because I wasn't breathing properly.)
My God, this is a strange but useful place, isn't it? Is there anything that wouldn't get useful answers. And silly ones as well, which are just as important.