Why Do I Experience Breathlessness Everytime I Laugh for a Long Time?

Question

My case is that of mild asthma and I have been having this disease for the past four years. I have never had any trouble with it especially since I stopped doing athletics but every time I laugh out for a long time, I get breathless and there are occasions when my breathing becomes really heavy, too and by the time I decide to use my inhaler I feel o k. Can someone tell me why this is happening and what I should do? Thank you for your advice in advance.