An asthma trigger is something which can set off an asthma attack, a cascading series of reactions in which someone's airways constrict due to muscular spasms while mucus production increases, causing difficulty breathing. In some cases, an asthma attack can be fatal, as the airways may close entirely, making it impossible for someone to get the oxygen she or he needs. Every patient's asthma is different, and people may have very different asthma triggers.
No matter what triggers it, an asthma attack happens in the same way. People used to use terms like “intrinsic” and “extrinsic” asthma to describe different kinds of triggers, but these terms are considered outdated, because it is not the asthma which is different, but the triggers. Learning to recognize one's triggers is very important part of managing asthma.
Allergies are a very common asthma trigger. These can include environmental allergies to things like dust, feathers, pet dander, pollen, and fungi. They can also include food allergies. When someone with asthma eats a food to which he or she is allergic, an asthma attack can occur as the body mistakenly identifies the food as something dangerous and goes on the offensive.
Stress can also act as an asthma trigger, with some people experiencing attacks in response to extreme emotions. Exercise can be another trigger, in which case the attacks may be called “exercise-induced asthma.” Other asthma triggers include certain medications, upper respiratory infections, acid reflux, smoking, strong odors, and even things like changes in temperature and humidity. Some people, for example, have difficulty breathing in extreme heat or cold.
With some patients, it may be necessary to take a medication for asthma management and to carry a rescue inhaler with medications which can be administered when an asthma attack occurs. If a patient starts using a rescue inhaler very frequently, it indicates that the maintenance medication should be adjusted or changed to gain better control over the patient's asthma. It is also useful for friends and family members to be aware of asthma triggers so that they can help patients avoid them or avoid putting patients in situations where they will be exposed to them.
Patients can undergo challenge testing to identify a specific asthma trigger or array of triggers. In this testing, the patient is exposed to carefully controlled doses of a suspected asthma trigger to see whether or not there is a reaction. Medical support is available in case the patient experiences a severe attack.