I used to suffer badly from it when I was younger and lived next to a busy main road in London. Giving up smoking and leaving London seemed to do the trick, long-term. Short term, it was the tablets.
Being ill and not being able to go to school did have its good side. I actually learnt lots of far more useful information by watching the schools programmes at home on the TV.
It was at this period that I went off the piano accordian big-time. My father used to say that my wheezing chest sounded just like one.