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How to Use Your Metered-Dose Inhaler

Know how to hold your inhaler? When to use a spacer? Learn the proper technique for using your metered-dose inhaler and when to replace it.

By Emily Gurnon, Contributing Writer

If you take asthma medication, you’re probably familiar with inhalers. They seem like simple devices, but if you don’t use them correctly, you may not get enough medicine where it needs to go — deep inside your lungs. That can keep you from getting the right amount of the medicine, making your asthma worse instead of better.

What is a metered-dose inhaler?
Metered-dose inhalers are built to release a measured amount of medicine each time you squeeze them. They have a canister that keeps the medicine pressurized, and a sleeve that you place in or near your mouth. Most people with asthma use a metered-dose inhaler for both long-term control medication and quick-relief treatment.

How do you use it?
Since it can be difficult to use an inhaler the right way, ask your doctor, nurse or pharmacist to show you how. Make sure you know how to hold it and when to breathe. Not all inhalers are used the same way.

Follow these general tips:

  1. Read and follow your inhaler’s instructions on priming and cleaning the device.
  2. To start, take off the cap that covers the mouthpiece and look inside to make sure nothing is blocking it.
  3. Hold upright and shake the inhaler.
  4. Stand up or sit up straight and take a deep breath in and then breathe out.
  5. Follow your doctor’s instructions to have the inhaler in your mouth, held away from your mouth or use a spacer.
  6. As you start to inhale, push down on the top of the canister. Breathe in slowly as deeply as you can. Keep breathing in slowly for at least 3 to 5 seconds.
  7. Hold your breath for 10 seconds if you can. Breathe out.
  8. If your doctor has told you to use two puffs of medicine, repeat steps 1 to 7 for the second puff.
  9. If you are using a corticosteroid, rinse your mouth out and spit. This will help prevent thrush.

Each time you visit your doctor, he or she should observe your inhaler technique. If you have questions, ask for a refresher course on how to use the inhaler.

Ways to avoid getting too little medicine
If you feel the inhaler is not helping as much as it should be, there may be an easy fix. Make sure you:

  • Take the cap off the inhaler before using it.
  • Breathe slowly and deeply when you press on the canister.
  • Breathe in through your mouth, not your nose.
  • Make sure your inhaler isn’t empty. See below for information how to determine this.
  • Talk to your doctor about using a spacer.

What is a spacer?
A spacer is a plastic tube that attaches to your inhaler. It is designed to help the medicine bypass your mouth and throat and get into your lungs. It can help you avoid common problems, like breathing in at the wrong time or breathing in too fast. It may also make you less susceptible to the mouth infection called thrush — a side effect of inhaled corticosteroid medicine, which is a medication in some inhalers.

One type of spacer is called a valved holding chamber. It has a valve at the mouthpiece, so you can’t accidentally breathe out into the tube. The chamber holds the medicine until you are ready to inhale slowly and deeply.

Your doctor can help you choose which type of device is best for you. Both children and adults can benefit from using a spacer.  Be sure to follow instructions on how clean and care for your spacer.

When does an inhaler need to be replaced?
Keep track of how often you use your inhaler. When you pick up your medicine, discuss when you will need to replace it with your pharmacist. If you are using an inhaler, ask your doctor if you should have two inhalers so you'll never run out.

It may seem that shaking your inhaler will tell you whether it’s empty or not. But what you hear inside may just be propellant, not medicine.

Some inhalers have a dose counter that indicates how much has been used. Or you can look at the instructions and find out how many puffs it contains.

In the past, you may have been told to drop your inhaler in water and see if it floats. This was thought to show you if it was empty. That is no longer suggested as a way to find out if you need to replace your inhaler. It is not reliable. Counting puffs as explained above or talking to your pharmacist are the best ways to know when to replace your inhaler.


National Heart, Lung, and Blood Institute. Expert panel report 3: Guidelines for the diagnosis and management of asthma. Accessed: January 20, 2016.
National Heart, Lung, and Blood Institute. How is asthma treated and controlled? Accessed: January 20, 2016.
American Lung Association. Valved holding chambers and spacers. Accessed: January 20, 2016.
UptoDate. Patient information: Asthma inhaler techniques in adults. Accessed: January 20, 2016.

Last Updated: January 29, 2016