Im the king(Or queen?)of loosing sleep.
Its not because of lack of sleep, all that ever happens to me is hearing voices, and hallucinations. Which happened alot this past week during exams.
But asthma is caused by things inflaming etc. in the end like Audrey said airway constricts. Get an inhaler which I think causes your heart to speed up, and allows you to breathe better.
Or you could go the utterly stupid route, have one never use it even with a asthma attack. After 2 years I used it once because of never using it. I "Trained" myself to become less dependent, even in very dangerous situations. But hey I dont worry about it anymore, and never weaze as much.