What is the course of disease (with and without treatment) for acute asthma?

Better to treat: Acute asthma implies there are symptoms which should be treated - left untreated the condition can worsen and in some cases be life threatening. The most common mistake I see in asthma treatment is lack of using a SPACER - a plastic pipe like device that helps improve the amount of medication delivered to lungs. http://www.cdc.gov/asthma/management.html

Hard to say: Asthma is not a "One size fits all" problem. For some it is so minor they just cough when the seasons change, some will die of their attack if untreated. Some with rather minor asthma can go through a life threatening event when a simple aggravating factor like the flu or bronchitis triggers the attack.Modern treatments can allow most to achieve good control and minimize risk.