Why has asthma increased in children less than 18 years old?

Lots of reasons: It may be due to increased awareness of the disease, so instead of calling it something else we are diagnosing asthma. It may also be due to our environment. We are aware of certain countries where asthma is lower. It tends to be in less developed countries or even in areas where they let livestock live in their homes. We may be keeping our kids too clean!

Pollution: The more pollution and ozone problems the more asthma is stimulated.