Using an inhaler sounds simple, but nearly half of people who use one make at least one critical mistake that reduces how much medication reaches their lungs. The good news: once you learn the correct sequence, it becomes second nature. Below is a detailed, step-by-step walkthrough for the two most common inhaler types, along with the mistakes to avoid and the maintenance habits that keep your device working properly.
Metered-Dose Inhaler (MDI) Step by Step
The metered-dose inhaler is the classic L-shaped device with a metal canister pressed into a plastic case. It delivers a pre-measured spray of medication when you press the canister down. Getting the technique right comes down to coordinating your hand and your breath, which is exactly where most people struggle.
Preparation
Remove the mouthpiece cap and shake the inhaler vigorously for about five seconds. Hold it upright with your index finger on top of the canister and your thumb supporting the bottom of the plastic case. If the inhaler is brand new or hasn’t been used in several days, you need to prime it by spraying one to four puffs into the air (check your specific inhaler’s instructions for the exact number). Priming clears the valve and ensures your first real dose delivers the right amount of medication.
Inhalation
Stand or sit upright. Breathe out gently and fully, emptying your lungs as much as you comfortably can. Place the mouthpiece between your teeth and close your lips tightly around it so no air escapes around the sides. Begin breathing in slowly and deeply through your mouth, and as you start that breath, press the canister down once with your index finger to release a single puff. Continue breathing in slowly and steadily until your lungs feel completely full. This slow, deep breath is essential: it carries the medication deep into your airways rather than slamming it against the back of your throat.
Remove the inhaler from your mouth and hold your breath for 5 to 10 seconds. This pause gives the tiny medication particles time to settle onto the walls of your airways, where they do their work. Then breathe out slowly through your nose or pursed lips.
If You Need a Second Puff
Wait 30 to 60 seconds before your next puff. Shake the inhaler again before each dose. Repeat the full sequence: exhale, inhale slowly while pressing the canister, hold your breath, then exhale. Replace the cap when you’re finished.
Dry Powder Inhaler (DPI) Step by Step
Dry powder inhalers look different from MDIs. They come in various shapes (disc, tube, or cylindrical designs) and don’t spray medication. Instead, the powder is pulled into your lungs entirely by the force of your own breath. This means the breathing technique is the opposite of an MDI: you need a strong, steady inhalation rather than a slow, gentle one.
Preparation
Hold the inhaler with the mouthpiece facing up. Load a dose by following your device’s specific mechanism. On a Flexhaler, for example, you twist the colored grip fully in one direction and then fully back until you hear a click. That click confirms a dose is loaded. Do not shake a DPI after loading, as this can dislodge the powder from where it needs to be. If your DPI is brand new, prime it according to the package instructions (the Flexhaler requires two twist cycles before the first use, then never again).
Inhalation
Hold the loaded DPI level and away from your mouth. Breathe out gently and fully, but never exhale into the mouthpiece. Even a small amount of moisture from your breath can clump the powder and ruin the dose. Place the mouthpiece between your teeth and seal your lips around it. Breathe in strong and steady, filling your lungs completely. Because the device relies on your airflow to pull the powder out, a weak breath means less medication reaches your lungs.
Remove the inhaler and hold your breath for about 10 seconds, then exhale slowly. You may not taste or feel anything, or you might notice a faint sweet flavor. Either experience is normal. If a second dose is prescribed, repeat the full loading and inhalation steps. Wipe the mouthpiece with a dry cloth when you’re done.
Using a Spacer With an MDI
A spacer (sometimes called a valved holding chamber) is a tube that attaches to the mouthpiece of your MDI. It solves the biggest problem people have with MDIs: timing the press-and-breathe step. You spray the medication into the spacer first, then inhale from the chamber at your own pace. This makes coordination almost effortless and significantly increases the amount of medication that actually reaches your lungs instead of coating your mouth and throat.
To use one, attach the spacer to your MDI, shake the inhaler, breathe out fully, seal your lips around the spacer’s mouthpiece, press the canister once, and then inhale slowly and deeply. Hold your breath for 5 to 10 seconds. If you didn’t get a full breath, you can inhale a second time from the spacer before the medication settles, holding your breath again for about 5 seconds. Only spray one puff into the spacer at a time.
The Three Most Common Mistakes
A large review of inhaler studies found that errors have remained stubbornly common over the years, even as device designs have improved. For MDI users, the three biggest problems are almost equally frequent: about 45% of people fail to coordinate pressing the canister with their breath, 44% breathe in too fast or too shallow, and 46% skip the breath-hold after inhaling. Each of these mistakes means less medication reaches the small airways where it’s needed.
DPI users make a different set of errors. Nearly 30% don’t prepare or load the device correctly, 46% forget to exhale fully before inhaling, and 37% skip the breath-hold. Forgetting to breathe out before your dose is a particularly costly mistake because your lungs are already partially full, leaving less room for the medicated air to travel deep into your airways.
If your asthma or COPD symptoms aren’t well controlled despite regular medication use, poor technique is one of the first things worth checking. Ask your pharmacist to watch you use your inhaler and point out any errors. It takes less than a minute, and the difference can be dramatic.
Rinsing Your Mouth After Steroid Inhalers
If your inhaler contains a corticosteroid (a preventer or controller medication), rinse your mouth, gargle, and spit the water out every time you use it. Steroid particles that linger in your mouth and throat can cause oral thrush, a fungal infection that appears as white patches and soreness, along with hoarseness and a sore throat. Rinsing washes away deposited medication before these side effects develop. This step isn’t necessary for rescue inhalers that contain only a bronchodilator.
Cleaning and Maintenance
Medicine residue builds up inside your inhaler over time and can partially block the spray nozzle, reducing your dose. Clean your inhaler at least once a week.
For an MDI, pull the metal canister out of the plastic case and remove the mouthpiece cap. Rinse only the plastic parts under warm running water for about 30 seconds. Let everything dry completely before reassembling. Never let the metal canister get wet. Once the case is fully dry, push the canister back in and test the inhaler by spraying a single puff into the air.
For a DPI, never use water. Moisture will clump the powder and stop the device from working properly. Instead, wipe the inside and outside of the mouthpiece with a clean, dry cloth.
Knowing When Your Inhaler Is Empty
Many newer inhalers have a built-in dose counter that ticks down with each puff. If yours has one, replace the inhaler when the counter reaches zero. Some canisters continue to spray propellant even after the medication is used up, so you can’t rely on whether something comes out.
If your inhaler lacks a dose counter, the old advice of floating the canister in water is no longer recommended. Manufacturers have specifically warned against it because the float test was designed for older propellants and gives inaccurate results with modern formulations. Worse, submerging the canister can damage the valve seal.
A more reliable method is to weigh the canister on a kitchen scale. For a standard 200-dose rescue inhaler, a full canister weighs around 29 grams, a half-full canister about 22 grams, and an empty one 15 grams or less. When the weight drops to 15 grams, replace it. The simplest approach, though, is to note the date you start using a new inhaler, check how many doses it contains, and calculate roughly when it will run out based on your daily use.