Triggers are what cause your child's asthma symptoms to flare up. They can be found everywhere — in your home, in your car, on the playground, in his classroom, in his bed. Each child's trigger is different. Some may be visible (pollen, mold), while others may seem hidden (cold viruses, ozone). The first step is to work with your child's health care provider to determine what his triggers are and spell them out in his action plan. Then, you have a course to follow — to avoid those triggers so that your child can better control his asthma.