What do I need to know about asthma triggers?

Asthma is a lung disease that makes breathing difficult. Asthma causes inflammation or swelling of the airways - the tubes that carry air to the lungs. This swelling can cause wheezing, coughing, shortness of breath, and chest tightness.

Being around certain things can set off, or “trigger”, asthma symptoms. An asthma trigger is something that causes the airways to swell and become narrow, making it hard to breathe.

An asthma trigger can be an allergen or an irritant. An allergen is something that causes an allergic reaction in the body. Some examples of allergens include:

• furry pets, like cats, dogs, rabbits, etc.
• dust mites
• pollens, like from grasses, flowers, weeds, etc.
• moulds
• air pollution
• certain medicines.

Irritants are things that you're not allergic to, but that bother your airways and cause narrowing or tightening. Some common irritants include:

• cigarette smoke
• cold air
• hot, humid air
• strong smells, such as perfume
• chemical fumes, like those from cleaning products
• exercise
• the cold virus or a chest infection
• laughing or crying hard
• stress.

Not everyone with asthma reacts to the same triggers. The key is to figure out what triggers your asthma symptoms and then avoid those things as much as possible.

Figuring out your asthma triggers

You might notice that your asthma flares up when you exercise outside in winter. Or maybe you get breathing problems when people smoke around you. Some triggers can be avoided easily - exercise indoors in winter if cold air is a problem. And don't allow people to smoke around you. Some triggers cannot be completely avoided, but you can do a lot to control your exposure to them.

Here are some tips for dealing with common triggers:

Triggers	What I can do to avoid or manage these triggers?
Hard exercise	Warm up before playing sports or exercising to relax the airways Ask your doctor about taking medication before you play sports
Cigarette smoke	Stay away from smoky places. Ask your friends and family to not smoke in your house or car.
Chemical fumes, like those from household cleaners, paint fumes, oven cleaners, etc.	Switch to non-toxic brands of cleaning products. Ask another family member or friend to do household cleaning chores. Wear a protective mask when dealing with chemicals.
Pets	Find a loving home for your pet. If you keep your pet, keep it out of your bedroom and off the furniture. Have someone wash and brush your pet weekly.
Dust mites - tiny bugs that live in dust. Dust mites are especially concentrated in mattresses, pillows, carpet, and bedding.	Cover your mattress and pillow with airtight plastic or vinyl covers. Tape the zipper for a complete seal. Keep the humidity in your house below 50%. If you can, remove carpets, rugs, and heavy curtains from your bedroom. Vacuum rugs and carpets at least once a week. Wash your bedding in hot water and dry it in a hot dryer every 7- 10 days. Dust weekly with a damp cloth, and wear a respirator as you dust.
Pollen - grasses, weeds, flowers, trees	Close your windows to keep pollen out. In hot weather, spend more time indoors where there is an air conditioner. Avoid being outside in hot sunny weather, especially when pollen counts are highest.
The common cold, viruses, and chest infections	Wash your hands often. Get a flu shot every year in the fall to avoid getting sick. If you do get sick, ask your doctor about increasing your asthma medications.

Additional resources

• Adult information: asthma and exercise - Ontario Lung Association
• Allergies - University Health Network
• Dust Mites and Asthma - The Children's Asthma Education Centre