Inhalers fall into three main categories: metered-dose inhalers (MDIs), dry powder inhalers (DPIs), and soft mist inhalers (SMIs). Each delivers medication differently, and the right choice depends on your condition, your age, and how well you can coordinate breathing with the device. Beyond these handheld options, nebulizers offer an alternative for people who can’t use standard inhalers effectively.
Metered-Dose Inhalers (MDIs)
MDIs are the most common type of inhaler. They use a small pressurized canister to push a pre-measured dose of medication into your lungs as a fine mist. You press down on the canister and breathe in at the same time. That coordination, pressing and inhaling simultaneously, is the biggest challenge with MDIs. If your timing is off, much of the medication lands in your mouth and throat instead of reaching your lungs.
A spacer or valved holding chamber can solve this problem. These are tube-shaped attachments that fit between the inhaler and your mouth. They hold the medication in a small chamber for a moment, giving you extra time to inhale. Spacers increase the amount of medication that actually reaches your lungs while reducing side effects like throat irritation and oral thrush, which are common when steroid medications deposit in the mouth. For children and older adults who struggle with hand-breath coordination, a spacer makes MDIs far more effective.
Dry Powder Inhalers (DPIs)
DPIs deliver medication as a fine powder instead of a spray. Unlike MDIs, they don’t use a propellant, so there’s no need to coordinate pressing a canister with your breath. Instead, your own inhalation pulls the powder into your lungs. You load a dose (by twisting, clicking, or piercing a capsule, depending on the device), then breathe in quickly and deeply.
The catch is that DPIs require a strong, fast inhalation to work properly. If you can’t generate enough airflow, the powder won’t break into particles small enough to reach the small airways in your lungs. This makes DPIs a poor fit for young children, people having severe breathing attacks, and some elderly patients. Common DPI devices include the Ellipta, Turbuhaler, and Diskus.
Soft Mist Inhalers (SMIs)
Soft mist inhalers, like the Respimat, release medication as a slow-moving mist that lasts longer than an MDI spray. The mist travels more slowly and lingers in the air for about 1.5 seconds, compared to a fraction of a second with an MDI. This gives you more time to breathe it in and makes coordination easier. SMIs don’t require the forceful inhalation that DPIs demand, either. They work well for people who struggle with both MDI timing and DPI airflow requirements.
Nebulizers
Nebulizers aren’t handheld inhalers. They’re machines that convert liquid medication into a continuous mist you breathe through a mouthpiece or face mask over 5 to 15 minutes. They’re the go-to option when someone simply cannot use a handheld inhaler, whether because of age, coordination problems, or the severity of their symptoms during a flare-up.
Three types of nebulizers exist: jet nebulizers, ultrasonic nebulizers, and mesh nebulizers. Jet nebulizers are the most widely used and work by pushing compressed air through liquid medication. Ultrasonic nebulizers use high-frequency vibrations to create the mist. Mesh nebulizers push liquid through a fine mesh with thousands of tiny holes, producing a very consistent aerosol. Mesh models tend to be smaller, quieter, and faster than jet nebulizers.
For infants, small children, and elderly patients with cognitive difficulties, a face mask is the preferred delivery method. A mouthpiece works better for older, cooperative children and adults because it delivers more medication to the lungs and less to the surrounding air.
What Each Inhaler Type Treats
The device type is separate from the medication inside it. Inhalers deliver several categories of drugs, and some devices combine multiple medications in one.
- Short-acting bronchodilators (rescue inhalers): These relax airway muscles within minutes and are used for sudden symptoms like wheezing or shortness of breath. They typically come as MDIs.
- Inhaled corticosteroids (controller inhalers): These reduce inflammation in the airways over time and are taken daily to prevent symptoms. Available as MDIs and DPIs.
- Long-acting bronchodilators: These keep airways open for 12 to 24 hours and are used for ongoing conditions like COPD. They come in DPI and SMI formats.
- Combination inhalers: These contain two or even three medications in one device, reducing the number of inhalers you need to manage. Dual-therapy inhalers pair a corticosteroid with a long-acting bronchodilator. Triple-therapy inhalers add a second type of bronchodilator on top of that.
Two triple-therapy inhalers are currently available for COPD. Trelegy Ellipta is a DPI taken as one inhalation once a day. Breztri Aerosphere is an MDI taken as two inhalations twice a day. Both combine an anti-inflammatory steroid with two different types of long-acting bronchodilators in a single device, simplifying what used to require two or three separate inhalers.
How to Pick the Right Type
Your doctor will consider several factors when recommending an inhaler, but understanding the tradeoffs helps you ask the right questions. MDIs are versatile and widely prescribed, but they require good coordination or a spacer. DPIs eliminate the coordination problem but demand a strong breath. SMIs split the difference, needing less coordination and less airflow. Nebulizers are reserved for situations where handheld options aren’t practical.
Technique matters more than most people realize. Studies consistently show that a large percentage of inhaler users don’t use their devices correctly, which means the medication never fully reaches the lungs. If you’ve been using an inhaler and it doesn’t seem to work well, the issue may be the device rather than the drug. Switching to a different inhaler type, or adding a spacer to your MDI, can make a real difference.
Some newer inhalers now come with digital sensors that attach to the device, track when and how you use it, and send data to a smartphone app. These can remind you to take your medication and help your doctor identify patterns if your symptoms aren’t well controlled. They’re not widely prescribed yet, but they’re becoming more available, particularly for asthma maintenance inhalers.
Inhalers for Children
Children under 5 or 6 generally use an MDI with a spacer and face mask, since they can’t coordinate MDI timing or generate the airflow for a DPI. As children get older and more cooperative, they can transition to a mouthpiece on the spacer, which delivers medication more efficiently than a mask. By school age, many children can learn to use an MDI with a spacer alone, and by their teens, most can handle DPIs as well.
When a child is too distressed or too young for any handheld device, a nebulizer with a face mask is the standard alternative. The key during nebulizer treatments is that the child breathes quietly with the mask fitting snugly against their face. Crying actually reduces the amount of medication reaching the lungs because it changes breathing patterns and causes more of the mist to deposit in the upper airway.