why preventers with long acting relievers?

i was just wondering why you had to be on a preventer to go on a long acting reliever? is it just that if your in a stage of treatment where you need a long acting reliever you should have a preventer , or does it make the reliever one work better? and does it matter for a few days (i have forgoen one and not the other in the past) thanks in advance!

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Not sure of the detail, but I seem to remember reading that long acting relievers on their own can rarely cause problems with your heart. Something in the steroid preventer counteracts that.

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It's because recent studies have shown that when long acting beta agonists are used without a steriod there's a small increase in the risk of severe and life threatening asthma attacks. This is because Long acting beta agonists don't help the underlying inflammation of the airways.