Asthma is a condition in which the airways in your lungs narrow and swell. When asthma is triggered, the muscles around these airways tighten.

Some symptoms can include:

There’s currently no cure for asthma, but treatment and lifestyle measures can help manage your symptoms. One way is to reduce your exposure to allergens in the environment that can trigger your asthma.

An air purifier may help reduce exposure to environmental triggers.

An air purifier is a portable air cleaner. It filters and traps pollutants from the air inside your home. It also sanitizes the air that comes through it. One of the most popular types of air purifiers is an ionizing air purifier, which uses an electric field to trap particles.

An air purifier vs. an air filter

An air purifier is different than an air filter, which traps pollutants by forcing the air through a filter. While both devices trap and filter out pollutants, only an air purifier sanitizes the air.

An air filter may be part of a heating, ventilation, and air conditioning (HVAC) system, or it may be a portable device.

Several types of filters may be used in both devices, including:

  • washable
  • disposable
  • high efficiency particulate air filter (HEPA)
  • carbon

An air purifier vs. a humidifier

Air purifiers and filters are different than humidifiers, which add moisture to the air to prevent dryness. Humidifiers don’t have any effect on allergens or other environmental triggers of asthma, but they may help you breathe more easily.

If you do use a humidifier, be careful not to add too much humidity to the air, as it can cause mold or dust mites. Washing a humidifier frequently can also help keep mold from growing inside. Both devices can make your asthma worse if not maintained.

Common environmental asthma triggers inside your house include:

An air purifier can remove these triggers from your home by trapping them in the filter. It works by bringing in air and trapping these small particles, then releasing the clean air. An air purifier also sanitizes the air around it.

However, research shows mixed or inconclusive results as to whether air purifiers help asthma symptoms.

For instance, a small 2018 study involving 50 people allergic to dust mites suggests that air purifiers may be helpful in relieving asthma symptoms. However, the study authors recommend more research to learn more about how air purifiers could help.

A 2018 research review suggests therapeutic interventions, such as air purifiers, may be better at reducing allergens when combined with other methods, especially HEPA vacuums and pest control. The review authors concluded that more research evaluating specific asthma measures in a larger population sample is required. More specific research can help provide meaningful insight into intervention outcomes.

According to the U.S. Environmental Protection Agency, you can know how effective an air purifier will be in your home based on its Clean Air Delivery Rate (CADR). This number should be at least 2/3 of the area of the room where your purifier will be. The Association of Home Appliance Manufacturers provides different CADR’s for dust, tobacco smoke, and pollen.

A purifier should be in good condition. This includes routine maintenance like replacing filters when necessary.

Overall, how well an air purifier can help with asthma symptoms depends on the:

  • airflow rate of the purifier
  • filter design
  • size of the allergen particles
  • location of the purifier in your home

Only air purifiers that remove small particles will help asthma symptoms. If possible, it should meet HEPA requirements, which means it will filter very small particles. For best results, make sure your air purifier can filter and sanitize the air.

Some types of air filters have two filters: one for gasses and one for particles. The combined cleaning efforts of these filters can help you get the best clean air.

You should also make sure your purifier is the correct size for the room where you want to clean the air. You may need multiple air purifiers if you want to purify a large room or more than one room.

Some air purifiers produce a type of gas called ozone. Be sure to avoid these products. The ozone can irritate your lungs and worsen your asthma symptoms. In addition, this type of purifier only sanitizes the air. It doesn’t remove particles from it.

Be aware that while air purifiers can reduce mold particles and odors, they can’t solve a mold problem. If you have mold in your house, take steps to clean it directly. You may need someone else or a professional service specializing in mold removal to do this so that it doesn’t lead to an asthma attack.

Other ways to help reduce allergens in your home include:

  • Using an air conditioner: Pet dander, dust, and other allergens are removed from the air.
  • Cleaning regularly in damp areas: This can help prevent mold from forming in areas like the bathroom.
  • Cleaning regularly in other areas: If your house gets dusty, wear a mask to protect yourself.
  • Using dustproof covers on your mattress and pillows: Dust mites can gather on mattress and pillow surfaces.
  • Washing your bedding regularly: Hot water can help get rid of allergens on sheets, blankets, and pillows.
  • Vacuuming at least once a week: Use a high quality vacuum to avoid putting dust back in the air.
  • Getting rid of objects and materials that can trap dust and other allergens: This includes surface clutter. Carpets also trap a lot of allergens, so consider hardwood floors if you have asthma.
  • Keeping your windows closed during pollen season: This is especially important if you don’t have air conditioning.
  • Grooming or bathing pets regularly: This can help reduce dander.

The most important way to manage your asthma is working with your doctor to create a treatment plan and consistently following it. Your treatment plan will likely include medication, but it may also include steps that you can take on your own to help avoid asthma triggers.

Steps that you can take include:

  • Maintaining a moderate weight: Having overweight or obesity can make asthma worse and lead to other health problems.
  • Trying breathing exercises: Breathing exercises may help open your airways and teach you to breathe in ways that will not trigger asthma.
  • Exercising regularly: Regular exercise may help decrease your asthma symptoms by improving your lung health. The right type of exercise is key. If exercise triggers your asthma, talk with your doctor about how to work out safely.
  • Avoiding weather triggers: Covering your nose and mouth in cold or windy weather may help prevent an asthma attack or prevent asthma symptoms from worsening.
  • Managing stress: In some cases, stressful events can trigger asthma. Knowing how to effectively manage your stress may help prevent an asthma attack.
  • Avoiding heartburn triggers: If you have symptoms of heartburn or gastroesophageal reflux disease (GERD), avoiding triggers may help prevent an asthma flare-up. If at-home remedies don’t work, talk with your doctor about treatment options.

Even if you’re following your treatment plan, it’s important to consult your doctor or get medical attention if:

  • your symptoms get worse, especially if you feel your medications aren’t working or you’re using a quick-relief inhaler more often
  • you have any changes in your symptoms
  • you have shortness of breath with minimal activity
  • you have an asthma attack that’s not helped by a quick-relief inhaler — in this case, get emergency treatment right away

Avoiding environmental allergens that can trigger asthma symptoms is an important part of managing asthma.

There’s some evidence that air purifiers can help reduce and even get rid of these allergens. If you do use an air purifier for asthma, make sure it can trap small particles, as well as filter and sanitize the air.

Cleaning and vacuuming regularly, using an air conditioner, and getting rid of carpets and items that can trap allergens are also effective ways of reducing asthma triggers.