Page header image

Asthma: Controlling Triggers



  • Asthma is a chronic lung disease that can cause shortness of breath, coughing, wheezing, and sometimes chest tightness.
  • Symptoms can get worse when your child is exposed to asthma triggers such as smoke, pollen, mold, dust, or other things in the environment.
  • Limiting exposure to these triggers can help prevent problems for your child.


Asthma is a long-lasting (chronic) lung disease. It can cause shortness of breath, coughing, wheezing, and sometimes chest tightness.

Asthma symptoms are caused by two different problems in the airways:

  • One problem is that the tiny muscles around the airways tighten up, which causes shortness of breath, coughing, wheezing, and sometimes chest tightness.
  • The other problem is redness, swelling, irritation, and too much mucus in the airways.

If your child has asthma, symptoms often start after your child is exposed to a trigger. Asthma triggers can include:

  • Exercise and other physical activity
  • Allergies such as dust, pollen, mold, or animal dander
  • Something that irritates the lungs such as cold air, smoke, or strong smells such as paint, soap, candles, or perfume
  • Nonsteroidal anti-inflammatory medicines (NSAIDs) such as aspirin, ibuprofen, and naproxen
  • An infection such as a cold, the flu, or a sinus infection
  • Strong emotions or stress
  • Indigestion or heartburn, also called gastroesophageal reflux disease, or GERD. If your child often has problems with indigestion you may have more asthma symptoms, especially while lying down.

Try to limit your child’s contact with these triggers, especially in places where your child spends a lot of time such as at home and school or work. Your child should keep a rescue inhaler with him or her at all times in case your child has an asthma attack.


Cigarette, pipe, cigar, and marijuana smoke are harmful to children and adults in general, but the smoke is a bigger problem for children with asthma. Children who breathe secondhand smoke often have symptoms such as coughing, wheezing and a tight feeling in the chest.

Thirdhand smoke is made up of harmful chemicals left on surfaces from tobacco or marijuana smoke. It stays on carpet, floors, walls, clothes, and other surfaces for a long time. Children can be exposed to these chemicals by touching a surface and then touching their mouth or nose. Even the smell of smoke on clothes can trigger asthma symptoms in a child with sensitive airways. Children who live in a household with people who smoke are also less likely to outgrow their asthma.

Children with asthma should not spend any time in places where there is smoke. No one should smoke in the home, and no one should smoke in a car that a child with asthma rides in. Airing out cars and homes does not get rid of thirdhand smoke.


Pollens are small particles that plants such as trees, grasses, and weeds release into the air. The amount of pollen in the air outdoors varies with the season and the time of day. Pollen and outdoor mold amounts tend to be lower in the early morning and higher at midday and in the afternoon.

Pollens from grasses, weeds, and trees are lightweight and can be carried in the air for miles. These pollens land in the eyes, nose, and airways, causing allergies and asthma. Flower pollens are heavier and are carried from plant to plant by insects rather than the wind. As a result, flower pollens rarely cause allergies. Although it is hard to avoid pollens completely, some suggestions include:

  • Keep your windows shut, especially in your child's bedroom, and use central air conditioning during pollen seasons. If a room air conditioner is used, recirculate the indoor air rather than pulling air in from outside. Air purifiers can be helpful if filters are kept clean. HEPA (high efficiency particulate air) filters are best. Wash or change air filters once a month or according to the instructions that came with the product.
  • After being outside during allergy season, your child should shower and change clothes right away. Do not keep the dirty clothes in bedrooms because there may be pollen on the clothes.
  • Mow the lawn often. This limits the amount of pollen released. Your child should not be in the immediate area when the lawn is being mowed. Consider replacing the lawn with gravel or stone.


Molds are found year-round throughout the house, outdoors, and in foods, but especially in areas of high moisture. Molds blow around in the air both outdoors and indoors. Bathrooms and damp basements are common areas for mold growth. Mold is also likely to grow in evaporative (swamp) coolers, humidifiers, bathrooms, and the refrigerator drip pan and crisper. Here are some ways to decrease mold growth:

  • Light and ventilation prevent mold growth. In the bathroom, clean the tile, floors, shower curtain, and tub thoroughly and often. Also clean under the sink. Use a cleaning solution that kills molds. For example, you can use diluted household bleach (1 cup of bleach in 10 cups of water). Be sure to open windows in the area when using bleach to avoid breathing in the fumes.
  • Repair leaky faucets and pipes. Try to get rid of leaks and standing water.
  • Use paint rather than wallpaper on your walls. Enamel paint stops mold growth better than latex paint. An antifungal substance can be added to paints to keep mold from growing.
  • It is best to keep the humidity in the house between 30 and 50%. Buy a dehumidifier to take moisture out of the air if you live in a humid climate. Dehumidifiers can help keep mold from growing in damp areas such as basements. Look for areas that get damp from hard rains and fix any leaks that you find. Empty water from and clean drip pans often.
  • Avoid evaporative coolers, vaporizers, and humidifiers with a reservoir, if you can, because they are ideal places for mold and bacteria to grow. When these appliances are operating, molds and bacteria can be sprayed throughout the house. If you do use one, empty the reservoir daily, clean it with soap and water, and dry it thoroughly. The reservoir should be refilled just before use.
  • Greenhouses, compost piles, and homes with many plants also frequently have molds. Cover the potting soil of houseplants with foil to reduce the spread of mold spores.

House dust

Many things are in house dust, including dirt, insect debris, dust mites, molds, animal dander, dead skin, food crumbs, and bacteria. Dust collects on every item in the home, including mattresses, couches, clothes, rugs, drapes, and stuffed animals. It is hard to avoid house dust, but the following ideas will help:

  • Avoid clutter and dust catchers, particularly in the bedroom. These include knickknacks, wall decorations (pictures, pennants, and fabric wall coverings), drapes, shades or blinds, stacks of books, and piles of papers or toys.
  • Give your child washable, "nonallergenic" stuffed toys when possible. For children who want to sleep with soft toys, keep only one or two soft toys in the bed, and wash them every week in hot water (at least 130° F). Store toys, dolls, and play equipment outside the bedroom or in the closet.
  • Keep the bedroom closet door closed. Vacuum the closet floor often. Store only in-season clothes in the closet.
  • Bare floors are best. You can replace carpet with washable, nonskid rugs. Damp mop the floors often. If you have carpet, vacuum often and thoroughly. Change vacuum cleaner filters often. Vacuum and dust early in the day to let dust settle before nap or bedtime. It is best to vacuum when your child is not home or to keep your child in another area of your home for 30 to 60 minutes after you vacuum. Be sure to clean under the furniture and in the closet.
  • Mattresses should be in woven microfiber coverings that are allergen-proof. You can get allergen-proof coverings where bed linens are sold. Zippers or openings should be taped. Use only polyester pillows. Cover pillows with allergen-proof covers or wash the pillows each week in hot water. Also wash blankets, sheets, and pillowcases in very hot water (hotter than 130° F, or 54.4° C) every week. Cooler water used with detergent and bleach can also work. Avoid products made of feather, wool, kapok, or foam. Replace pillows every 6 to 12 months.
  • Forced-air furnaces and air conditioners should have a dust-filtering system. Filters should be changed every 2 to 4 weeks. Filters can be cut to cover room vents if the central furnace filters are not changed every 2 weeks. Have cold and warm air ducts professionally cleaned at least every 4 to 5 years.


Allergens are found in animal saliva, dander, and urine. They cause allergic reactions in many people. Children may be more sensitive to one type of animal, such as cats, than another type. All furry animals can cause allergic reactions. Cold-blooded reptiles, such as snakes, turtles, lizards, and fish, do not cause problems.

If your child is sensitive to animals and has a pet, the best thing is to remove the pet from your home. Giving away a family pet is hard, but if your child is sensitive, it may be necessary. Once the pet is gone, thoroughly clean the house. It is especially important to clean stuffed furniture, wall surfaces, rugs, drapes, and heating and cooling systems.

If you keep a pet your child is sensitive to, the pet should live outside and never be in the child's bedroom, family room, playroom, or kitchen. Keep your child’s bedroom door closed. Keep pets out of any room where a child with asthma sleeps. It may help if you do these things:

  • Bathe pets weekly. Check with your vet if you have questions about how often you can bathe your pets.
  • Wash hands right after any contact with a pet.
  • Have non-allergic family members wash, brush, or comb pets, or clean out animal cages or litter boxes outdoors.
  • Change furnace and air conditioner filters regularly.


Cockroaches and their droppings are a major trigger and worsen asthma symptoms. To get rid of cockroaches:

  • Keep food and garbage in containers with tight lids. Take garbage out often.
  • Never leave food out. Especially keep it out of bedrooms. Do not leave out pet food or dirty food bowls.
  • Vacuum or sweep the floor, wash the dishes, and wipe off countertops and the stove right after meals.
  • Plug up cracks around the house to help stop cockroaches from getting in.
  • Do not store paper bags, newspapers, or cardboard boxes.
  • Use bait stations and other environmentally safe roach poisons. Keep these products away from children and pets.

Exercise and other physical activity

In exercise-induced asthma, your child may have symptoms:

  • During or after physical activity and when breathing is hard, heavy, or fast
  • When the air is cold
  • When the humidity is low or high
  • When there is a lot of air pollution
  • When there are a lot of allergens in the air

Your child does not need to avoid all exercise and other physical activity. Doing warm-up exercises before a vigorous workout may help prevent an asthma attack. Your child can usually avoid symptoms by using a rescue inhaler 15 to 30 minutes before exercise.

Air pollution

Different types of indoor and outdoor air pollutants can aggravate asthma. This includes ozone, dust, smoke, paint fumes, and strong perfumes or odors. Weather conditions such as cold temperature and low humidity can make asthma worse, especially on high-pollution days.

  • Check news services for the daily pollution index and pollen count.
  • Avoid unnecessary physical activity outdoors on days when the pollution index or pollen count is high.
  • Avoid using a wood burning fireplace or stove, kerosene heater, or unvented gas stove or heater.
  • Avoid indoor exposures to perfume, talcum powder, hair spray, air fresheners, fabric softeners, new carpet or particleboard, or other strong odors or sprays.


Sulfites are a food preservative found in certain foods such as shrimp, canned tuna, dried fruit, pickles, olives, and other foods. Rarely, sulfites can cause severe asthma in some children.


Aspirin exacerbated respiratory disease (AERD) can trigger asthma by taking aspirin or other NSAIDs. Aspirin, ibuprofen, and naproxen are NSAIDs. This kind of asthma is not common in children.

If your child has asthma, use NSAIDs such as ibuprofen with caution. Do not give aspirin to children 18 years or younger unless told to do so by your healthcare provider. This is due to the risk of Reye syndrome, an illness that causes inflammation of the brain and liver.

Colds and Flu

Colds and flu make asthma worse and often trigger episodes of asthma. To help prevent colds and flu:

  • Help your child avoid close contact with people who have a cold or the flu.
  • Have your child stay at least 6 feet away from people who are sick and avoid crowded places if you can.
  • Teach your child to wash hands before eating and when exposed to others who may have a cold or the flu.
  • Keep surfaces clean, especially bedside tables and surfaces in the bathroom. Some viruses and bacteria can live for hours on surfaces such as cafeteria tables, door handles, and desks. Wipe them down with a household disinfectant according to directions on the label.
  • Stay up to date with the recommended immunizations (shots) for your child including flu and COVID-19. Ask your healthcare provider about any other vaccines your child or your family may need.
  • Take care of your child’s health. Help your child get at least 7 to 9 hours of sleep each night and eat a variety of healthy foods. Your child should be physically active as advised by your child’s provider. Talk to your child about the risks of smoking and using e-cigarettes, drinking alcohol, and using drugs.
Developed by Change Healthcare.
Pediatric Advisor 2022.1 published by Change Healthcare.
Last modified: 2021-12-07
Last reviewed: 2021-06-15
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2022 Change Healthcare LLC and/or one of its subsidiaries
Page footer image