Although we don’t know what causes asthma, we do know that asthma is a very common disease.  At least 8 million children in the United States have asthma.   For some reason, more boys are affected than girls. In the year 2000 there were about 41⁄2 million office visits for asthma and over 700,000 emergency room visits for asthma.  Approximately 200,000 children were hospitalized for asthma in 2000. Kids miss over 14 million school days each year because of asthma.  Parents miss many days of work because they have to take care of a child who is sick from asthma. 

In general, about one out of every 10 children has asthma. You probably know other adults or children with asthma. There is a good chance that many people you know have asthma, but you just don’t know that they have it.