Many children with asthma can breathe normally for weeks or months between flares. When flares do occur, they often seem to happen without warning. Actually, a flare usually develops over time, involving a complicated process of increasing airway obstruction . All children with asthma have airways that are overly sensitive, or hyperreactive , to certain asthma triggers. Things that trigger asthma flares differ from person to person.
Some common triggers are exercise, allergies, viral infections, and smoke .
The sensitive airway linings react to trigger exposure by becoming inflamed, swollen, and filled with mucus. The muscles lining the swollen airways tighten and constrict, making them even more narrowed and obstructed. Diagnosing asthma can be tricky and time-consuming because different children with asthma can have very different patterns of symptoms. For example, some kids cough constantly at night but seem fine during the day, while others seem to get frequent chest colds that don't go away. It's not uncommon for kids to have symptoms like these for months before being seen by a doctor.