People with asthma may have triggers that cause their condition to flare. Common triggers include dust mites, air quality, tobacco smoke, mold spores, pet dander, and strong smells.

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Asthma is a condition that causes a person’s airways to become swollen. This leads to the airways narrowing, making it difficult to breathe. Asthma can cause shortness of breath, chest tightness, wheezing, and coughing that tends to worsen during the night or early morning.

An asthma attack is the sudden worsening of symptoms. A person may experience difficulty breathing, wheezing, and a rattling sound in the chest. The duration can vary and may last a few minutes, hours, or days.

Asthma attacks often occur when a person has exposure to triggers.

Though not everyone has the same response to all stimuli, the following are several common triggers that may trigger a person’s asthma to flare and become worse.

This article examines common triggers of asthma. It also looks at what a person should do if they experience an asthma flare-up.

Dust mites are microscopic creatures that are present in many homes.

Some people can have an allergic reaction to the fecal matter and body parts of dead dust mites. For individuals with asthma, the allergic reaction may trigger an attack.

How to avoid and prevent dust mites

The Centers for Disease Control and Prevention (CDC) suggest that people can help prevent dust mite-induced asthma attacks by:

  • avoiding down-filled comforters, quilts, and pillows
  • washing bedding every week and drying it completely
  • placing allergen-proof pillow and mattress covers on bedding
  • aiming for relative humidity levels that range between 30–50%
  • cleaning and vacuuming area rugs, floors, and carpets regularly using a high-efficiency particulate absorbing (HEPA) filter

Poor air quality can cause a person with asthma to experience asthma attacks.

Some causes of poor air quality include:

  • dust
  • cigarette smoke
  • ozone, smog, and other sources of air pollution
  • charcoal grills
  • wood fires
  • chemicals
  • strong vapors, odors, or fumes, such as paint, gasoline, scented soap, or perfume

How to avoid poor air quality

It may not be possible to avoid all sources of air pollution that can trigger asthma attacks. However, individuals can take some steps to limit their exposure.

Some tips to help avoid pollution include:

  • closing windows if neighbors are burning wood, leaves, or other debris
  • avoiding being near people who are smoking
  • avoiding strongly scented soaps, body washes, or shampoos

The CDC also suggests listening to local air pollution forecasts and organizing activities outside when air pollution levels are low.

People with asthma should not smoke tobacco, and they should avoid being around people who are smoking whenever possible.

Secondhand smoke can also trigger an asthma attack.

How to avoid tobacco smoke

The laws regarding tobacco use inside public areas vary from state to state, but many have smoke-free designated areas, such as in front of shops and in bars and restaurants.

A person with asthma should take steps to avoid establishments where smoking is allowed.

Parents of children with asthma who smoke may also wish to consider quitting or limiting where and how often they smoke.

Learn more about 11 tips for giving up smoking.

Mold can cause an asthma attack in anyone, even if they are not allergic to it.

Mold often grows in moist or damp areas of the home, which can include places such as:

  • basements or garages
  • bathrooms
  • kitchen
  • anywhere moisture can become trapped

How to prevent and avoid mold

A person can help reduce their exposure to mold by:

  • fixing leaky plumbing or other causes of leaking water
  • scrubbing mold off surfaces
  • opening a window or using a vent when showering
  • making sure to dry wet or damp items within 24–48 hours
  • replacing any absorbent material with mold growing on it
  • cleaning the refrigerator and air conditioner’s drip pans regularly
  • maintaining a low indoor humidity level with a dehumidifier or air conditioner
  • checking humidity levels with a hygrometer throughout the day and making any necessary adjustments

Pets with fur or feathers can cause an asthma attack if a person is allergic to them.

Pet dander refers to tiny pieces of skin that fall off dogs, cats, rodents, and other animals. Even if a person does not have a pet, mice and cockroaches in the house can cause exposure to dander.

Additionally, short-haired and bald dogs or cats can still cause an allergic reaction or trigger an asthma attack. The American Lung Association states that no dog or cat is allergen-free.

How to prevent and avoid pet dander

The CDC recommends taking the following steps to reduce pet dander:

  • using mattress and pillow covers that prevent allergens
  • ensuring that pets are kept out of the bedroom
  • using a HEPA filtration air purifier
  • washing pets with fur frequently

Pollen can cause hay fever, which can affect a person’s asthma. A 2017 article notes that pollen exposure contributes to increased numbers of hospital admissions due to worsening asthma symptoms.

The different types of pollen can include:

  • tree pollen
  • weed pollen
  • grass pollen

Additionally, thunderstorms can lead to worsened symptoms of asthma because the rain hits the pollen, breaking them up. The wind then spreads the pollen around, which makes them easy to inhale.

How to avoid pollen

A person can reduce the effects of pollen exposure by:

  • ensuring they have their reliever inhaler on them at all times
  • taking a preventer inhaler in line with instructions from a healthcare professional
  • taking antihistamine medications

Individuals can also use a pollen calendar to help understand which pollen triggers their hay fever or asthma.

Disinfectants and cleaning products can trigger an asthma attack. This is because they contain chemicals, strong scents, and volatile organic compounds (VOCs).

Cleaning supplies and other household products that contain VOCs include:

  • aerosol spray products
  • chlorine bleach
  • air fresheners
  • detergents
  • dishwashing liquid
  • oven cleaners
  • furniture polish
  • floor polish
  • cleaners for rugs and upholstery

Precautions to take when cleaning

A person can help avoid triggering an asthma attack by:

  • avoiding overuse of the products and following a schedule for cleaning to avoid overuse
  • using safer products, such as soap and water
  • avoiding using bleach or mixing disinfectants
  • avoiding products containing fragrances
  • ensuring there is plenty of airflow while cleaning
  • using the products safely and correctly

Other common triggers of asthma include:

  • Weather: Dry wind and cold air can trigger an asthma attack.
  • Emotional stress: Strong emotions can cause a person to hyperventilate, leading to an asthma attack. People can speak with a medical professional about medications and methods to help reduce their stress levels.
  • Health conditions: Certain conditions can lead to asthma attacks, including:
  • Infections: Infections that affect the lungs and airways can trigger an asthma attack. To help reduce the chance of contracting infections, a person should ensure they wash their hands frequently and thoroughly. Infections may include:
  • Exercise: Exercising can cause a person to breathe heavily. Physical activity can also lead to exercise-induced bronchoconstriction, a form of asthma. With proper treatment, a person will not need to limit their physical activity.
  • Medications: Aspirin can trigger an asthma flare-up. Beta-blockers can also make it more difficult to control asthma. People should speak with a healthcare professional before taking these medications.

During an asthma attack, a person should try to remain calm and use the medication their doctor prescribed to help treat an acute attack.

A healthcare professional will typically prescribe the use of a quick-relief medication, often in the form of an inhaler, that will work quickly to open up the airways. These medications can include short-acting, rapid-onset beta2-agonists and anticholinergic bronchodilators.

If a person’s inhaler is ineffective, they may need inhaled or systemic corticosteroids to help reduce inflammation in the lungs.

A person should speak with a doctor if their symptoms persist or their fast-acting medication becomes less effective.

Learn more about what to do at home for an asthma attack.

Asthma is a chronic condition that causes difficulty breathing during an asthma attack. Several known, common triggers may trigger a person’s asthma, such as allergens, pollution, and dust.

The best strategy an individual can take is to limit their exposure to known triggers. If an asthma attack occurs, a person should use the fast-acting medication their doctor prescribed and let them know if anything changes.