Asthma generally affects all age groups but often starts in childhood.Children who often have respiratory infections and wheeze often are at higher risk of developing asthma.In United States , there are around 25 million with asthma among which more than 7 million are children.
When it comes to sex , girls have less asthma than boys which is quite opposite in adults where more women have asthma than men.But as of now, role of sex hormones in asthma is not known.