Asthma Inhalers

Medically Reviewed by Dan Brennan, MD on December 06, 2022
7 min read

How well do you know your asthma inhaler? What does it do for you? What drugs are in it? Do you puff and breathe, or breathe and puff?

Inhalers are the most effective way to get lifesaving medications to people with asthma and other lung diseases. Whether you have asthma or care for someone who does, here’s what you need to know about inhalers, including how to use one correctly.

An asthma inhaler is a handheld device that delivers medication straight into your lungs. You get the drugs faster -- and with fewer side effects -- than you would if you took it by pill or IV.

Asthma inhalers can deliver drugs in a variety of ways.

Hydrofluoroalkane inhalers (HFAs)

Formerly called metered dose inhalers (MDIs), HFAs give the drug through a small, handheld aerosol canister. They work like a spray can. You push the inhaler, it sprays out the medicine, and you breathe it in. A tube-like gadget called a spacer can help kids or people with trouble breathing use an HFA more easily.

Using an HFA without a spacer

  1. Take the cap off your inhaler and shake it well.
  2. Hold the inhaler with your index finger on top of the canister and thumb on the bottom of the plastic mouthpiece.
  3. Sit up straight or stand up. Tilt your head back slightly and breathe out all the way.
  4. Open your mouth wide, and place the inhaler about 2 inches in front of your mouth. (Or you can put the HFA in your mouth, between your teeth, with your tongue flat under the mouthpiece and your lips sealed.)
  5. Breathe in and out one time.
  6. Press the metal canister down and breathe as deeply as you can for about 3 to 5 seconds
  7. Hold your breath for the length of time specified for the medicine you are taking to allow the medication to reach your lungs.
  8. Wait at least a minute, then repeat for each puff your doctor tells you to take.
  9. Replace the cap on your inhaler when you’re finished. If your inhaler contains a steroid, gargle and rinse your mouth with water or mouthwash after each use.

Using an HFA with a spacer

The contents of an HFA are under pressure and are released quickly, making it difficult to properly inhale the particles. The spacer chamber suspends these particles until you or your child breathes in, making it easier to get the medication into the lungs. These devices are recommended for children who have trouble coordinating breathing and using an inhaler the way they should, especially those younger than 5 or 6. Adults should also use a spacer chamber, especially if they have problems using an HFA. Spacer chambers can keep particles from collecting in your mouth or tongue, lessening side effects from medications. Spacer chambers should not be used with a dry powder inhaler (DPI).

How do you use a spacer device?

  1. Remove the caps from the HFA inhaler and spacer chamber. (Add a spacer device if needed.)
  2. Shake the canister well.
  3. Insert the HFA into the back end of the spacer chamber.
  4. If there is a spacer device such as a mask, place it over your child's nose and mouth, making sure there is a good seal. If there is just a mouthpiece, the tip should go between the teeth, with lips wrapped tightly around to make a good seal.
  5. Breathe out completely, or have your child breathe out completely.
  6. Press down firmly on the canister to release one puff of the medication into the spacer chamber.
  7. Hold the mask firmly in place while your child takes at least six breaths. If your child is using a spacer chamber with a mouthpiece, after inhaling the medication, they should hold their breath for 5 to 10 seconds and then breathe out slowly. Some spacers will make a horn-like sound if you breathe too quickly. This means you need to slow down on your next breath.
  8. Wait 1 minute.
  9. Repeat steps 2 through 7 for each puff of medication ordered.
  10. When the treatment is complete, remove the HFA from the space chamber. Replace the caps on the asthma inhaler and spacer.
  11. If using this device with an HFA that contains a steroid, wipe your child's face with soap and water to remove any medication. If possible, rinse their mouth with water. Adults can gargle and rinse their mouth with water or mouthwash.

How do I care for an HFA with a spacer?

Clean the spacer chamber every other day. If you aren’t using it often, you may need to clean it only once a week. Let it air dry, and store it in a clean, dry place when you're not using it.

How do I know when an HFA is empty?

The number of puffs contained in a metered dose inhaler is printed on the side of the canister. After that number of puffs has been used, you must throw out the inhaler, even if it continues to spray. Keep track of how many puffs you or your child has used. Many HFA brands also have built-in digital counters that show how many puffs are left.

If your child or an adult uses an HFA every day to control asthma symptoms, you can figure out how long it will last by dividing the total number of puffs in the HFA by the total puffs used every day. For example, if the HFA has 200 puffs and they use four puffs per day, divide 200 by four. In this case, the HFA would last 50 days. Using a calendar, count forward that many days to learn when to discard the HFA and begin using a new one.

If you use the inhaler only when necessary, keep track of how many times you spray the inhaler. If you prefer, you can obtain a device that has a counter to count down the number of puffs each time the inhaler is pressed. Ask your child's doctor for more information on these devices. In general, it is important to be aware of how many doses remain in the HFA. Even when the medication is used up, the HFA can still release a spray of propellant that can be mistaken for a spray of medicine.

Dry powder inhalers (DPIs)

These require you to breathe in quickly and deeply. That can make them hard to use during an asthma attack when you can’t fully catch a deep breath. Read the instructions carefully if you get a different brand, because they vary widely and the new one may not work the same way your old one did.


These deliver medication through a mouthpiece or mask. They’re easier to use because you can breathe normally. That makes them good for children or people with severe asthma who may not be able to use an HFA or DPI the way they should.

Many inhalers contain steroids, like prednisone, to treat inflammation. Others have a type of drug called a bronchodilator to open up your airways. Some have both – this is known as a combination inhaler.

Anti-inflammatory asthma inhalers prevent asthma attacks and reduce swelling and mucus in your airways. They include:

For in-depth information, see WebMD's article on Asthma, Steroids, and Other Anti-Inflammatory Drugs.

Bronchodilator asthma inhalers are either short- or long-acting. They widen your airways to ease symptoms like wheezing, shortness of breath, and coughing. They include:

  • Short-acting beta-agonists (ProAir HFA, Proventil HFA, Ventolin HFA, Xopenex)
  • Long-acting beta-agonists (Foradil, Serevent). The combination inhalers containing both a long-acting beta-agonist and a steroid include Advair, Dulera, and Symbicort.
  • Long-acting anticholinergics such as tiotropium bromide (Respimat, Spiriva), for anyone age 6 or older. This medicine can be used along with your regular maintenance medication. Trelegy Ellipta combination inhalers include both an anticholinergic and a long-acting beta agonist as well as a corticosteroid.
  • Combivent and DuoNeb inhalers contain both albuterol and ipratropium (a bronchodilator); albuterol and ipratropium may also be given using a nebulizer.

Many new inhalers include a dose counter to show how much medication is left. It’s hard to tell with older models, most of which make a puff sound long after the medication is gone. This could be a serious problem if you need the inhaler and it’s empty.

The best way to tell how many doses remain is to mark the number of doses used on the inhaler and then toss it after you've used this number of puffs. You can find the total number of doses on the box or canister. Mark the date on your calendar when you expect to use all of the available puffs in the new inhaler, and replace it before then. Keep one or two extra quick-relief inhalers at home.

  • How often should I use my long-acting inhaler? This type of inhaler is designed to keep your airways open and help prevent attacks.
  • When should I use a rescue inhaler? This type is meant to work quickly to open narrow airways and ease your symptoms.
  • How do I use the inhaler? More than half of people who use an inhaler don’t use it correctly. If you have trouble, a device called a spacer can help.
  • What do I do if the inhaler doesn’t work well enough? If your medication doesn’t help with your symptoms during an attack, an asthma action plan can tell you when to get medical help.
  • Are there any side effects? Some asthma medicines can cause noticeable problems, especially if your dosage isn’t quite right or you don’t take them the way you should.