How to Use an Asthma Inhaler Correctly: A Step-by-Step Guide
▶ Inhaler technique: the key facts
Up to 90% of inhaler users make at least one technique error that reduces drug delivery to the lungs. The two most common mistakes with a pMDI are pressing the canister before starting to inhale (instead of coordinating them), and inhaling too fast. With a DPI, the most common error is inhaling too slowly instead of fast and deep. Ask your pharmacist or practice nurse to observe your technique at every review.
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Getting the most from your inhaler depends almost entirely on technique. Studies have consistently shown that poor inhaler technique reduces the amount of drug reaching the lungs — in some cases by more than 50%. This means that if you are not using your inhaler correctly, you may think your asthma is poorly controlled when the issue is actually suboptimal drug delivery.
Correct technique is different for different device types. A pMDI (pressurised metered-dose inhaler, the classic aerosol “spray” inhaler) requires slow, steady inhalation. A DPI (dry powder inhaler) requires fast, deep inhalation. Using pMDI technique on a DPI — or vice versa — will dramatically reduce effectiveness.
Have your technique checked regularly. NICE guidelines recommend inhaler technique is checked at every asthma review. Even experienced users can develop errors over time.
How to Use a pMDI Inhaler (Step-by-Step)
A pressurised metered-dose inhaler (pMDI) is the classic aerosol inhaler — used by Ventolin Evohaler, Clenil Modulite, Fostair 100/6, and many others. Follow these steps precisely:
- 1
Remove the cap and shake
Remove the mouthpiece cover. Shake the inhaler vigorously for 5 seconds. If using for the first time or not used for ≥7 days, prime it by spraying 2 test puffs into the air away from your face.
- 2
Breathe out gently
Breathe out slowly and gently to empty your lungs. Do not breathe out into the mouthpiece — this adds moisture and may clog the device.
- 3
Position and seal
Hold the inhaler upright, with your index finger on top and thumb below. Place the mouthpiece in your mouth between your teeth. Close your lips to form a tight seal around the mouthpiece. Tilt your head slightly back.
- 4
Begin to breathe in slowly, then press
Start to breathe in slowly and steadily through your mouth. As you begin to inhale, press the canister down once. Continue to breathe in slowly and deeply for 3–5 seconds. This coordination of inhalation and pressing is the hardest part — the most common error is pressing before you start to breathe in.
- 5
Hold your breath
Remove the inhaler from your mouth. Hold your breath for 10 seconds (or as long as comfortable, minimum 5 seconds). This allows the aerosol particles time to settle in the lungs before you breathe out.
- 6
Breathe out slowly
Breathe out slowly and gently through your nose or away from the mouthpiece.
- 7
Wait 30–60 seconds before a second dose
If a second puff is required, replace the cap, wait 30–60 seconds, shake again, and repeat the process from step 2.
Tip: If you hear a rushing or spraying sound immediately and do not feel the aerosol going in, you may have fired the canister too early or too late relative to your inhalation. Using a spacer eliminates this coordination problem entirely.
How to Use a pMDI with a Spacer
Using a spacer with your pMDI is the recommended technique for most patients. It eliminates the need for perfect hand-breath coordination and significantly increases the amount of drug reaching the lungs.
- 1
Shake the inhaler and attach to the spacer
Remove the inhaler cap and shake vigorously. Insert the mouthpiece end of the inhaler into the back of the spacer. Check the spacer valve is present and moving freely.
- 2
Breathe out gently
Breathe out slowly to empty your lungs. Do not breathe into the spacer mouthpiece when doing this.
- 3
Seal your lips around the spacer mouthpiece
Place the spacer mouthpiece between your teeth and close your lips to form a complete seal.
- 4
Press the inhaler once
Press the canister down once to release one puff into the spacer chamber. Do not press a second time before inhaling.
- 5
Breathe in slowly and hold
Breathe in slowly and deeply through the spacer for 3–5 seconds. Hold your breath for 10 seconds (or as long as comfortable). Breathe out slowly through the spacer.
- 6
Wait 30 seconds before the next dose
For a second puff, wait 30 seconds, shake the inhaler again while still attached to the spacer, and repeat from step 3.
How to Use a DPI Inhaler
Dry powder inhalers (DPIs) work differently from pMDIs. They come in several formats — Accuhaler, Turbohaler, Ellipta, Nexthaler, Handihaler — but the general principles are the same. The key difference: you must inhale fast and deep, not slowly.
- 1
Load the dose
Prepare the dose according to your device instructions: click the lever on an Accuhaler, twist and click the Turbohaler, open the cover on an Ellipta. A click sound or dose indicator confirms loading.
- 2
Breathe out away from the device
Breathe out completely, but do not exhale into the DPI mouthpiece — moisture from your breath will clump the powder and reduce delivery.
- 3
Seal and inhale FAST and DEEP
Place the mouthpiece firmly in your mouth, seal your lips, and inhale as fast and as deeply as possible in one smooth, forceful breath. This is the opposite of a pMDI — the fast airflow is what disperses and carries the powder into the lungs.
- 4
Hold your breath
Remove the device from your mouth and hold your breath for 10 seconds (or as long as comfortable). This allows powder particles to settle in the lungs.
- 5
Close and store
Close the device according to instructions. Store in a dry place — moisture is the enemy of DPIs. Do not store in bathrooms.
DPIs are not suitable during a severe acute attack when you may not have enough inspiratory flow to disperse the powder effectively. If you are very breathless, use your reliever pMDI with a spacer instead.
Common Inhaler Technique Mistakes
| Mistake | Device | What to Do Instead |
|---|---|---|
| Pressing the canister before starting to inhale | pMDI | Begin inhaling first, then press as you continue to breathe in |
| Inhaling too fast (you hear it spray loudly) | pMDI | Breathe in slowly and steadily over 3–5 seconds |
| Inhaling too slowly | DPI | Inhale as fast and as deep as you can in one breath |
| Breathing out into the mouthpiece | All | Always breathe out away from the device before inhaling |
| Pressing 2+ puffs into spacer before inhaling | pMDI+spacer | One puff per inhalation only |
| Not holding breath after inhaling | All | Hold for 10 seconds after each puff |
| Not shaking the inhaler | pMDI | Shake vigorously for 5 seconds before each use |
| Storing DPI in a humid environment | DPI | Keep DPIs in a dry place; never in the bathroom |
When to Use Your Reliever Inhaler
Your reliever inhaler (blue, salbutamol) should be used:
- When you have acute asthma symptoms — wheezing, breathlessness, chest tightness or cough
- Before exercise, if your doctor has recommended this, to prevent exercise-induced symptoms
- During an asthma attack — 1 puff every 30–60 seconds, up to 10 puffs, while waiting for emergency help
If you need your reliever more than twice per week (other than for pre-exercise use), this is a sign that your asthma is not adequately controlled. Speak to your GP about starting or optimising a preventer inhaler.
If your reliever is not working — or if you need it more than every 4 hours — seek urgent medical attention. Call 999 if you are very breathless and cannot speak in full sentences.
Cleaning and Maintaining Your Inhaler
A poorly maintained inhaler can block the spray hole and reduce drug delivery. Follow these basic steps:
- pMDI: Remove the canister and rinse the plastic holder in warm water weekly. Allow to dry completely before reinserting the canister. Do not immerse the metal canister in water.
- Spacer: Wash monthly in warm soapy water. Allow to air dry (do not towel dry — this creates static). Replace every 6–12 months.
- DPI: Wipe the mouthpiece with a dry cloth only — never use water. Keep in a dry place.
- Check the dose counter: Many inhalers have a dose counter. Replace when the count reaches zero, even if the inhaler still seems to spray — later doses may not contain adequate drug.
For a comprehensive overview of asthma — causes, symptoms, diagnosis and all treatment options — see our complete asthma condition guide. [Pillar page — link to be activated on publication]
Frequently Asked Questions
How do you use a pMDI inhaler correctly?
Remove the cap and shake. Breathe out gently away from the mouthpiece. Place the mouthpiece in your mouth and seal your lips. Begin to breathe in slowly, then press the canister once as you continue to inhale. Breathe in slowly for 3–5 seconds total. Hold your breath for 10 seconds. Wait 30–60 seconds before a second dose. Using a spacer removes the need for precise coordination and is recommended for most users.
What are the most common inhaler technique mistakes?
The most common errors include pressing the canister before starting to inhale, inhaling too quickly (pMDI), inhaling too slowly (DPI), breathing out into the mouthpiece, firing multiple puffs into the spacer before inhaling, and not holding the breath after inhalation. Studies show up to 90% of inhaler users make at least one technique error. Ask a pharmacist or nurse to check your technique regularly.
How do I use an inhaler with a spacer?
Shake the inhaler and attach it to the spacer. Breathe out gently away from the spacer. Seal your lips around the spacer mouthpiece. Press the canister once. Breathe in slowly and deeply and hold for 10 seconds. Breathe out slowly. Wait 30 seconds before the next puff. Only one puff per inhalation — do not stack multiple doses in the spacer.
How do I use a DPI inhaler?
Load the dose per device instructions. Breathe out away from the mouthpiece. Place the mouthpiece in your mouth, seal your lips, and inhale FAST and DEEP in one smooth motion. Hold for 10 seconds. Never exhale into the DPI mouthpiece. Store in a dry place. Note: DPI technique (fast inhalation) is the opposite of pMDI technique (slow inhalation).
See also: Ventolin Evohaler: dosage, side effects and how to buy.
References
- NICE (2024). Asthma: diagnosis, monitoring and chronic asthma management. NG245.
- Usmani OS et al. (2018). Critical inhaler errors in asthma and COPD: a systematic review of impact on health outcomes. npj Primary Care Respiratory Medicine 28:43.
- Asthma + Lung UK (2024). How to use your inhaler.
- NHS (2023). How to use an inhaler. nhs.uk
- Lavorini F et al. (2008). Effect of incorrect use of dry powder inhalers on management of patients with asthma and COPD. Respiratory Medicine.