Asthma is a very common disease in the United States, where more than 17 million people are affected. A third of these are children. In 2002, 478,000 hospitalizations and 4,657 deaths were attributed to asthma.
Asthma is on the rise in the United States and other developed countries. We are not sure exactly why this is.

For more information see the source.
Another link gives the same information and a little more.
http://www.wrongdiagnosis.com/a/asthma/b...