An asthma trigger is something in the environment that triggers an asthma attack. If you're an asthma sufferer, an attack can be triggered when you become exposed to your particular trigger. When you become exposed to this trigger, you will experience an allergic reaction and your airways will narrow, so that you will have difficulty breathing. Triggers vary among sufferers, but some of the most common include dust, animal hair, and pollen. Whatever your particular trigger(s), it will require some detective work to figure out what your particular ones are.

To begin your investigation, start by keeping a log or diary of attacks. Note the time of day, what you were doing, and where you were when one happened. For example, you may have been vacuuming when you experienced an attack. In this case, it may be animal hair, dust mites and/or dust that trigger an attack for you. Another possible trigger may be cigarette smoke, the smell of perfume, or paint fumes. Outside, pollen, cold air or car fumes may be triggers as well.

Once you know what your triggers are, you can learn ways to avoid or at least minimize them. For example, if vacuuming triggers an asthma attack for you and you cannot get out of this duty, wearing a mask over your mouth and nose when you're vacuuming may minimize your exposure to dust and therefore minimize your chance of an attack. Medications will also help, and in some cases, your doctor may also be able to give you allergy shots that will greatly reduce your chances of an attack when you are being exposed to triggers. Certainly, you will be in situations where you won't know what a particular trigger is and therefore won't be able to avoid it. Therefore, medications and perhaps allergy shots are necessary regardless of whether or not you can completely avoid your known triggers in most situations. Allergy shots can build up your immune defenses and may ultimately negate some triggers, although the imperative term for asthma is "control" rather than cure.