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Asthma Triggers - Types and Prevention

Published on May 05, 2022 and last reviewed on Feb 06, 2023   -  6 min read


An asthma trigger is any breathable substance, type of activity, or environmental factor that may narrow the airways and evoke an asthma attack in an individual.

What Are Asthma Triggers?

An asthma trigger is any substance that can be breathed in by someone with asthma that causes the airways to become smaller, making it hard to breathe. Sometimes, it is a certain activity or emotional status or particular weather that triggers an asthma attack. Triggers vary from person to person. Hence, understanding the triggers helps one watch out and avoid them.

How Do the Triggers Start an Asthma Attack?

When a trigger is inhaled, it travels down the airways through the neck and chest into the lungs. The body tries to defend itself against the triggers. And it tells the muscles around the airways to tighten. As a result, the inside of the airways swells up and creates mucus to stop the triggers. Often, the body reaction is quite exaggerated in an asthmatic individual compared to a nonasthmatic individual.

What Are the Different Types of Asthma Triggers?

There are many types of asthma triggers. They cause similar symptoms in an asthmatic individual but in different ways:

  • Allergens - An allergen works inside the body, causing the immune system or body’s defenses to react. This reaction releases chemicals called histamines. Histamines can cause asthma and allergy symptoms, like congestion, itchy eyes, runny nose, and sneezing. People can be allergic to some triggers but not others.

  • Irritants - Irritants do not affect the body’s immune system the way allergens do but cause the nose to overreact, causing symptoms similar to allergens.

  • Other Factors - Including stress, exercise, weather conditions, food, and respiratory infections.

What Are the Common Allergens That Trigger Asthma Attacks?

Many allergens exist inside the house and outdoors. The common allergens are:

  1. Pollen is found outside but can be brought inside on clothes, shoes, and the body.

  2. Dust mites, which are too small to be seen but are found in every home. These mites live in mattresses, pillows, carpets, fabric covers, furniture, bedcovers, clothes, and stuffed toys.

  3. Animal danders like animal skin flakes, urine, and saliva.

  4. Pest droppings in the form of body parts of cockroaches and rodents like mice or rats.

  5. Molds that grow in damp areas, such as bathrooms, kitchens, and basements.

How Can One Prevent Allergens From Triggering Asthma Attacks?

1. One can limit the impact of pollen by keeping windows closed and using central heating and air conditioning if available in high pollen and mold seasons. While staying outside during high pollen days, one can remove shoes before entering the house and change clothes once they are inside.

2. Dust mites are found throughout the home; they can never be completely eliminated. But they can be reduced in number by vacuuming every week with a vacuum cleaner with high-efficiency particulate air filters. Dust with damp clothes by pouring cleaning supplies directly at the cloth rather than spraying them on the area. Avoid sweeping, which pushes dirt and dust into the air. Declutter the bedroom, and store loose items in plastic boxes. And encase mattresses, box springs, and pillows in allergy-proof covers. Wash blankets and sheets once a week in hot water. Choose washable stuffed toys and keep washing them often in hot water and dry them thoroughly. Clean the window covers such as blinds and curtains frequently to reduce dust mites.

3. The most effective way to avoid animal dander is to remove pets from one’s home. If this is impossible, keep pets outside the house or at least keep them outside the bedrooms where people with asthma sleep. Washing pets each week also helps avoid asthma attacks.

4. Pests, such as cockroaches and rodents, are attracted by food, shelter, and water. They are commonly found in kitchens. Hence, the house should be made less welcoming to pests by using appropriate strategies of pest management. Remove sources of food and water pests might find attractive, do not leave garbage out, store food in airtight containers, and keep garbage concealed. Clean up food crumbs and spilled liquids right away. Avoid eating or drinking in the bedroom.

Fill holes and cracks in walls around windows and in the foundation. One may try boric acid to eliminate cockroaches and rat traps instead of pesticide sprays. Limit the pesticide sprays to the infested area alone, following the instructions on the label carefully, and keeping the area well-ventilated. A person with asthma should stay out of the room or wear a mask when sprays or fumes are present.

5. Mold grows in moist areas, particularly where there are water leaks and poor air circulation, such as bathrooms, kitchens, laundry rooms, around windows, and even around potted plants. To prevent mold from developing, one must fix leaking pipes, use exhaust or portable fans, and open windows while showering, bathing, or running the dishwasher. Hang wet towels to dry thoroughly. In the laundry room, make sure the cloth dryer is vented to the outside. Remove stagnant water from refrigerator drip pans, air conditioners, and dehumidifiers. Drain indoor plant drip pots, and scrape mold from the soil.

Also, try to maintain indoor humidity between 30 % to 50 %. Humidity levels can be measured by hygrometers which are available at hardware stores. If mold occurs, wipe it off the hard surfaces using hot water and mild soap and dry the area completely. If absorbent materials become moldy, they may need replacing. Molds can also grow on leaves outdoors; hence one must remove the shoes before entering the house.

What Are the Common Irritants That Trigger Asthma Attacks?

The common irritants one may come across are:

  1. Smoke can be from many different sources, such as smoke breathed into the lung from cigarettes, electronic cigarettes, cigars, hookahs, or marijuana, second-hand smoke, breathed out by a smoker and inhaled by a person with asthma. Third-hand smoke is the smoke that sticks to clothing, furniture, and carpeting. Wood smoke and kerosene gas fumes that come from heating sources may also trigger an asthma attack.

  2. Chemicals, including cleaning products such as bleach.

  3. Air pollution includes foul air and tiny particles in the air that act as pollutants.

  4. Strong odors and sprays from products like perfumes.

How Can One Prevent Irritants From Triggering Asthma Attacks?

  1. Doctors say never smoke around a person with asthma, as smoking in a closed room causes the smoke to enter the duct system and move around inside the house. If someone must smoke, ask them to smoke outside the home. However, one should remember that the smoke remains in the smoker’s clothes, hair, and hands. Also, do not smoke in the car because the smoke will stick to the upholstery even if the window is open.

  2. Polluted air is saturated with dust, metal particles, smoke, poisonous gases, fumes, bacteria, and viruses which can all trigger asthma attacks in a prone person. The only way to prevent this is to create awareness about environmental pollution, plant more trees, avoid burning things on the outside and use air filters.

  3. People tend to use strong odors and scents around the house in the form of fried foods, perfumes, liquids, and spray products. Cleaning supplies, such as bleach and detergents, can trigger asthma. Hence, one may make lung-friendly cleaning products with mild soap, vinegar, and hydrogen peroxide. If scented cleaning products must be used, they should be used in well-ventilated areas. And a person with asthma should wear a mask when fumes are present. Also, using a fan and opening windows helps to reduce strong odors.

What Are the Other Factors That Trigger Asthma Attacks?

Emotional stress and physical exercise may trigger asthma attacks in an affected individual. Infections like the flu, common cold, sinusitis, or acid reflux are some of the other conditions. High humidity, cold air, and thunderstorms too may act as triggers. Certain types of food ingredients and preservatives have been found to cause asthmatic attacks in some people.


It is important to emphasize that asthma triggers are present inside the home, school, childcare settings, work, and outdoor environments. Families of those with asthma should stay aware of these triggers. Also, one should know how to reduce or avoid the triggers effectively to prevent asthma attacks. Along with the right medications, the doctor can help one adopt the most suitable asthma management plan.

Last reviewed at:
06 Feb 2023  -  6 min read




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