If you have asthma, your home’s humidity level can affect your health. Too little humidity and your nose and throat can become dry and irritated, making colds worse and asthma harder to control.

Too much humidity and allergens such as dust mites and mold may escalate, triggering allergic reactions or asthma attacks. Very humid air is also heavy, which may make it harder to breathe.

In general, indoor humidity levels that range from 30 to 50 percent may be best for those with asthma. This humidity level is also usually comfortable for most people.

Keeping the air at the right humidity level may help reduce asthma symptoms.

A humidifier adds either warm or cool moisture into the air in the form of vapor mist. It can help you regulate the humidity in your home but must be regulated and well-maintained or it may make asthma symptoms worse.

The indoor humidity level is affected by both air temperature and weather conditions outdoors. During cold weather, the air in your home may be dry. Indoor heating can add to the dryness.

If you live in a dry climate year-round, not enough moisture in the air may be a constant fact of life. In both instances, a humidifier can help you maintain just the right amount of indoor humidity.

There’s no medical consensus about the ability of humidifiers to alleviate asthma symptoms. However, if your indoor air is dry enough to adversely affect your airways and respiratory system, a humidifier may be helpful.


If you do decide to use a humidifier, here are a few things to know first:

  • Humidifiers can worsen asthma if they run nonstop or too high, making the air very humid.
  • If you fill your humidifier with tap water, airborne minerals from water may also irritate your lungs.
  • Humidifiers can also make asthma worse if they’re not cleaned regularly or properly. A dirty humidifier can harbor bacteria and fungi, which they release into the air.
  • Cleaning your humidifier with products containing chemicals or bleach may also be irritating to the respiratory system.

Humidity and dampness can occur in any type of climate, from hot to cold. Breathing in overly humid air can cause respiratory distress and exacerbate asthma.

Dehumidifiers are electrical appliances that remove water from air. Using a dehumidifier can help bring the humidity down in an overly humid home. They can also reduce the buildup of mold and dust mites.

If you already have mold in your home, a dehumidifier won’t remove it. It can, however, reduce or eliminate additional mold growth.

There’s no definitive answer about which is better — a humidifier or a dehumidifier — for people with asthma. It often depends on the specific individual and their asthma triggers. It can be confusing trying to decide which, if any, you need.

If your home becomes very dry at certain times of year, a humidifier can add humidity to the air, helping you breathe better.

If the reverse is true and you live in a damp environment, a dehumidifier may help make the air more comfortable to breathe.

Your current health needs should also be taken into account. Many people automatically reach for a humidifier when they have a cold or respiratory infection, assuming that breathing in moist air will help break up congestion. Some doctors recommend this as well.

Using a humidifier may make it easier for you to breathe in some instances but may also make a respiratory infection worse if you have asthma or an allergy to mold or dust mites.

If you or your child has asthma and you wish to use a humidifier:

  • Make sure it’s cleaned every 1 to 3 days and is free of mineralized crusts.
  • Change the filter weekly, or as often as is recommended by the manufacturer.
  • Use demineralized or distilled water to fill it, rather than tap water.
  • Wash it with natural cleansers such as white vinegar or mild dish soap, rather than bleach or chemical cleansers.

Humidifiers and dehumidifiers range in price and in specifications.


Before buying a humidifier, decide whether you want a warm- or cool-mist model. Also, make sure to take the size of your room into account. Features to look for in a humidifier include:

  • cost
  • number of output settings
  • easy to clean
  • timer or automatic shut-off feature
  • noise level

Product to consider

The Honeywell HCM350B Germ Free Cool Mist Humidifier has UV technology that kills bacteria, spores, and fungi in water.

Details: It also has a microbial filter that traps minerals. It’s quiet and easy to clean. An automatic output control feature helps you maintain the best humidity level for your home.

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Before buying a dehumidifier, consider the amount of dampness in your home and the size of the room where your dehumidifier will run.

Dehumidifiers come in several sizes. Small units typically remove around 30 pints of water a day. Large units can remove up to 70 pints.

Like humidifiers, dehumidifiers must be kept clean. Many need to have the water they capture manually removed. Features to look for in a dehumidifier include:

  • cost
  • size
  • noise level
  • easy to lift and clean
  • digital readout or other easy-to-access function so you can monitor your home’s humidity level
  • automatic shutoff valve or other safety controls that help prevent overheating or water overflow

Product to consider

If you need a large model, the Frigidaire FFAD7033R1 70 Pint removes 70 pints of water daily.

Details: It has an easy-to-read digital humidity readout feature, plus a window so you can gauge when it needs to be cleaned and have its water removed. The pint tank has a handle and splash guard, making it relatively easy to use. One negative is the unit is heavy, weighing around 47 pounds.

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Keeping your home’s air at an appropriate humidity level may help, but it’s not enough to control asthma completely.

If you have asthma, your doctor has probably prescribed controller and rescue medications for you. It’s important that you follow your doctor’s directions and continue to use any asthma prevention medications you are prescribed, even when your symptoms are under control.

In addition to taking your prescriptions, these tips may help you to better manage asthma:

  • Identify and avoid asthma triggers, such as pollen, animal dander, and dust mites.
  • Do not smoke or vape.
  • Avoid second- and thirdhand smoke.
  • Get a flu shot annually.
  • Avoid colds and viruses by washing your hands often and by avoiding people who are ill.
  • Get enough sleep.
  • Exercise regularly.

Asthma can adversely affect your quality of life but medical interventions can help significantly. If you have early warning signs of asthma, see your doctor. These may include:

  • shortness of breath
  • coughing
  • wheezing
  • exhaustion
  • tightness in the chest

Many people don’t know they have asthma until they have an asthma attack. If you experience an asthma attack, call 911 or your doctor immediately. Symptoms of an asthma attack include:

  • pain or tightness in the chest
  • severe shortness of breath or trouble breathing
  • uncontrollable coughing or wheezing

If your home has overly dry air, a humidifier may help make your environment more comfortable. For people with asthma, this can make the air less irritating and easier to breathe.

However, a humidifier can also make asthma symptoms worse if it’s not cleaned and maintained properly or promotes the growth of organisms that the person is allergic to.