Overview

When you have asthma, certain things can make your symptoms worse. These things are called triggers.

Things that you're allergic to can trigger your asthma. They may include:

• Dust.
• Dust mites. These are tiny, nearly invisible creatures. They live in bedding, carpet, and furniture.
• Cockroach droppings.
• Pet dander. Dander is loose skin cells (like dandruff) from dogs and cats.
• Indoor mould.
• Pollen.

Your asthma can be triggered by other things too, such as:

• Colds, influenza (flu), and sinus infections.
• Cigarette smoke, air pollution, and fumes from gas, oil, or kerosene heaters.
• Exercise. Many people have symptoms when they exercise.
• Dry, cold air.
• Medicines, such as aspirin or beta-blockers.
• Hormones, including those involved in pregnancy and menstrual periods. A woman's symptoms may change just before or during her period.

How to identify asthma triggers

If you avoid triggers, you can prevent some asthma attacks. Here are some ways to learn what your asthma triggers are.

• Identify possible asthma triggers.

  When you're around something that triggers your symptoms, keep track of it. This can help you find a pattern in what triggers your symptoms. Record triggers in your asthma diary or on your asthma action plan.

• Monitor your lung function.

  Watch for things like being short of breath, having chest tightness, coughing, and wheezing. Also notice if symptoms wake you up at night or if you get tired quickly when you exercise.

  If your doctor recommends it, measure your peak expiratory flow (PEF), or "peak flow." A trigger may not always cause symptoms. But it can still narrow your bronchial tubes, which makes your lungs work harder. To identify triggers that don't always cause symptoms right away, you can measure your peak flow throughout the day. Your peak flow will drop when your bronchial tubes narrow, so it will drop when you're near things that cause your airways to narrow.

• Be tested for allergies.

  Skin or blood testing may be used to diagnose allergies to certain substances. Skin testing involves pricking the skin on your back or arms with one or more small doses of specific allergens. The amount of swelling and redness at the sites where your skin was pricked is measured to find allergens you react to.

• Share your trigger record with your doctor.

  After you have found some things that may trigger your asthma, you and your doctor can make a plan for how to deal with them.