1.   Asthma episodes have traditionally been relieved by quick-acting medications called bronchodilators, which open the airways.

2.   Children learn to think of the warning signs of an impending asthma episode in these traffic-signal colors.

3.   During an asthma episode, airways may become inflamed and swollen, clogged with excessive mucus and squeezed by twitchy muscles in the airway walls.

4.   During an asthma episode, the airways of the lungs begin to narrow slowly.