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General information, not medical advice. This page describes what a spacer is and how two public health authorities describe its role with a metered-dose inhaler (MDI). Your inhaler and spacer come with their own instructions, and your doctor, pharmacist or nurse decides what suits you or your child. Nothing here covers which medicine to take, how much, or how often.
Short answer. A spacer is a tube or chamber that fits between an MDI and the mouth, holds the released medicine so it can be breathed in, and removes the need to time the press of the canister with the breath. Technique and breathing method vary by device and by medicine, so follow the instructions supplied with your inhaler and spacer and have a health professional show you.
What you need
- A metered-dose inhaler (MDI) with its dose counter and expiry date visible. See parts of an inhaler for the canister, actuator, cap and counter.
- A spacer that fits the inhaler’s mouthpiece. A valved holding chamber is a spacer with a one-way valve; that guide covers its parts and FDA classification.
- For people who cannot keep a seal around the mouthpiece, a face mask can be fitted to the spacer (see the AeroChamber mask size chart).
- The instructions that came with your inhaler and spacer. Brands differ, and the National Asthma Council Australia (NAC) notes that its checklists are simplified and that you should check the package insert for specific instructions.
Do you have to have a spacer for an inhaler?
MedlinePlus says that if you have a spacer you should use it because it helps get more medicine into your airways, and that you do not need a spacer for dry powder inhalers (see MDI vs DPI). Whether you or your child should use one is a question for your prescriber; MedlinePlus advises asking your health care provider which spacer is best for you or your child.
Is it more effective to use a spacer with an inhaler?
The NAC says that with a spacer “the medication is better delivered down into the small airways”, whereas without one it “will remain in the mouth and the back of the throat”. MedlinePlus says that using an MDI the wrong way means less medicine reaches the lungs and most stays in the back of the mouth. The NAC also says a spacer “takes away the need to coordinate between inhalation and actuation” of the inhaler.
How do you use an asthma spacer?
A spacer attaches to the mouthpiece of the MDI, and the person breathes the released medicine in through the spacer’s own mouthpiece. Both authorities stress the same general points: check the dose counter and expiry date before use, use the inhaler only as its instructions say, put one puff into the spacer at a time, and breathe in slowly. The NAC says a whistle from the spacer means the breath is too fast. Details such as whether the inhaler needs shaking or priming depend on the device, so read the instructions for your particular inhaler and ask a pharmacist, nurse or doctor to demonstrate. This page does not give a step-by-step method.
Do you breathe in and out of a spacer?
The two sources describe different breathing methods, which is why the manufacturer’s instructions and your clinician’s advice take priority. The NAC describes breathing in and out through the spacer, or alternatively one slow, deep breath. MedlinePlus describes breathing in slowly and deeply and then holding the breath. Ask your clinician which applies to your device and medicine.
How to use an inhaler with a spacer for a child
MedlinePlus says almost all children can use a spacer. The NAC says a mask is used with a spacer for people who have difficulty coordinating breaths, because babies and toddlers may not be able to close their lips around the mouthpiece or inhale correctly, and that the mask needs a good seal around the edges. Which mask size fits which age is covered in the mask size chart; a clinician should choose the device and show the technique for a particular child.
What can go wrong
- Several puffs sprayed into the spacer at once. The NAC calls this a common error.
- Breathing in too fast. A whistle means slow down (NAC).
- A poor seal. Gaps between mask and skin, or lips not closed around the mouthpiece (NAC, MedlinePlus).
- Not cleaning or replacing the spacer. Spacers need regular cleaning and eventual replacement; the interval differs between sources and products, so follow the instructions for your own spacer.
- Using an expired or empty inhaler. Check the counter and date each time.
When to get professional help
- The NAC says spacers should be checked by a doctor, pharmacist or nurse every 6 to 12 months to confirm the structure is intact (for example no cracks) and the valve is working.
- Take your inhaler to appointments so your technique can be checked (MedlinePlus), and ask them to show you how to tell when the inhaler is empty or nearly empty and how to clean the device (NAC).
- Ask about unwanted effects from the medicine, and which spacer or mask is right for you or your child.
- For breathing difficulty or an asthma emergency, follow your own action plan or call your local emergency number.
For a different delivery device, see what a nebulizer is.
FAQ
Do you have to have a spacer for an inhaler?
MedlinePlus says to use a spacer if you have one, and that dry powder inhalers do not need one. Ask your prescriber whether you should use one.
How do you use an asthma spacer?
The inhaler fits into the spacer, one puff goes in at a time and the medicine is breathed in slowly through the spacer mouthpiece. Follow your device instructions and have a health professional demonstrate.
Do you breathe in and out of a spacer?
The NAC describes breathing in and out through the spacer or one slow, deep breath, while MedlinePlus describes a slow, deep breath that is held. Your device instructions and clinician decide which applies.
Is it more effective to use a spacer with an inhaler?
The NAC says a spacer delivers more medication to the small airways and less stays in the mouth and throat, and MedlinePlus says it helps get more medicine into the airways.
How to use an inhaler with a spacer for a child?
A mask on the spacer helps when a child cannot seal their lips around the mouthpiece. A clinician should choose the device and show the technique; see the mask size chart linked above.
Sources
All sources checked 2026-11-04.
- MedlinePlus (NIH, National Library of Medicine), “How to use an inhaler – with spacer”: https://medlineplus.gov/ency/patientinstructions/000042.htm
- National Asthma Council Australia, “How to use a metered dose inhaler (puffer) with a spacer for adults”: https://nationalasthma.org.au/living-with-asthma/how-to-videos/how-to-use-a-puffer-with-a-spacer-for-adults
- National Asthma Council Australia, “How to use a metered dose inhaler with a spacer for children”: https://nationalasthma.org.au/living-with-asthma/how-to-videos/how-to-use-a-puffer-with-a-spacer-for-children
