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What Are Asthma Triggers?

One way to help manage your child's asthma is to avoid asthma triggers. Triggers are things that can make asthma flare-ups more likely to happen.

Common asthma triggers include:

  • respiratory infections, like colds, the flu, or COVID-19
  • allergies to things like pollen, mold, and pet dander
  • irritants and pollutants in the air, like cigarette smoke or smog
  • weather conditions, like cold and dry air, or hot and humid air
  • strong emotions, like laughing, crying, or feeling stressed
  • exercise

Kids can't avoid all triggers all the time. But watching carefully to learn what those triggers are and then helping your child avoid them can keep asthma symptoms under control.

What Are My Child's Asthma Triggers?

Triggers are different for each child. Some might cause asthma symptoms only at particular times of the year. Others might stop being a trigger as a child gets older and "outgrows" asthma.

You'll work with your doctor to find your child's triggers. The doctor may suggest keeping an asthma diary to record your child's symptoms and the medicines they use. You can also write down when and where symptoms happened to help you identify possible triggers.

If your doctor thinks allergies might be triggering asthma flare-ups, your child might need an allergy skin test.

How Can We Avoid Asthma Triggers?

If Infections Are a Trigger

Respiratory infections are the most common trigger of asthma flare-ups in kids. For kids with asthma, breathing problems triggered by colds can last days or even weeks after the cold has gone away.

They can be hard to avoid, but there are some things that can help. Teach everyone in your family to wash their hands well and often. Everyone age 6 months and older should get the annual flu vaccine and an updated COVID-19 vaccine. All babies should be protected against severe RSV infection, either by mom getting vaccinated during the pregnancy or through an antibody shot that babies get during or just before RSV season.

Vaccinating the whole family against these viruses is an important way to help protect kids with asthma, who are at greater risk for health problems if they get infected.

If Allergens Are a Trigger

Allergens (things that cause allergic reactions) are another common cause of asthma flare-ups. These triggers include:

It's impossible to avoid all allergens, but you can minimize them in your home. Focus on the rooms where your child sleeps and plays:

  • Keep these areas as clean and dust-free as possible. Vacuum and dust weekly, get rid of clutter, give away unneeded stuffed animals and wash other stuffed animals in hot water regularly.
  • Wash sheets weekly in hot water and get rid of feather pillows and comforters.
  • Use hypoallergenic covers for the mattress, box spring, and pillows.
  • Remove rugs and carpeting wherever possible.
  • Clean curtains (which should be washable) often.
  • Make sure damp areas like bathrooms, basements, and laundry rooms are cleaned often and properly ventilated to prevent mold and mildew. Run dehumidifiers in damp areas.
  • Don't use humidifiers.
  • Check your local mold and pollen count readings and plan indoor activities for windy days, which can lead to high counts.
  • Use bait traps or professional pest control to rid your home of cockroaches. Keep your kitchen clean and your house free of stacks of paper.

If Irritants Are a Trigger

Irritants can affect anyone — even someone who doesn't have asthma. They're not usually a serious problem, but for kids with asthma, they can lead to flare-ups.

Common irritants include:

  • perfumes
  • aerosol sprays
  • cleaning products
  • wood and tobacco smoke
  • paint or gas fumes
  • air pollution

Here are some ways to reduce household irritants:

  • If a product triggers your child's asthma, switch to an unscented or non-aerosol version of it.
  • Don't have wood fires in your home.
  • Keep your child away from areas where painting or carpentry work is being done.
  • If you cook on a gas stove, make sure your kitchen is well ventilated — to the outside, if possible.
  • Ban smoking in your home and car, and make sure your child avoids smoky environments (like restaurants or parties).
  • Consider buying an air cleaner for your home or running the air conditioning year-round (clean the filter regularly). Also check air quality reports. On days when the quality is especially bad, keep your child indoors with the air conditioning on.

If Extreme Weather Is a Trigger

Some weather conditions can trigger asthma flare-ups, including:

  • windy conditions (which may stir up pollens and molds)
  • heavy rain (which can make trees and grasses produce more pollen)
  • extreme cold or heat
  • humidity or very dry air

If weather conditions are a trigger, keep an eye on the forecast and limit your child's time outdoors on problem days. If cold weather is a trigger, cover your child's nose and mouth with a scarf. If hot, humid weather is a problem, keep your child in an air-conditioned environment.

In some cases, your child's medicine dose may need to be increased.

If Exercise Is a Trigger

Exercise might be the only trigger for some kids with asthma. Along with allergens, this is one of the more common triggers. It can be a particular problem in someone whose asthma isn't well-managed. But this is one trigger that your child should not avoid because exercise is important for overall health.

Don't discourage being active or playing sports. Instead, talk with the doctor about what your child should do before, during, and after exercise. This may include taking medicine before working out or playing a sport.

If Reflux Is a Trigger

Gastroesophageal reflux is when the contents of the stomach flow backward into the esophagus. Some kids also inhale these contents into the lungs, which can harm airways and make asthma worse.

If reflux is a trigger, treating it can help your child's asthma symptoms.

Medically reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: March 2024