Asthma affects more than 22 million Americans and is on the rise.

Did your city make the list?

Asthma is a chronic disease of the airways that makes breathing difficult. Many things in the environment can trigger an attack, including air pollution, secondhand smoke, and pollen. While there are no asthma-free cities, some are more challenging than others for people living with asthma. The Asthma and Allergy Foundation of America (AAFA), a nonprofit patient organization, has released their "2008 Asthma Capitals." Here are the top 10.