What Are Inhalers, and How Do They Work?

An inhaler is a medical device that delivers medication directly into the lungs. By bypassing the digestive system, inhalers allow fast, targeted treatment with minimal side effects compared to oral drugs.

There are three main delivery styles:

Metered-dose inhalers (MDIs) — use propellants to push a measured dose of medication into the lungs.

Dry powder inhalers (DPIs) — rely on the user’s breath to draw the medicine in.

Soft mist inhalers (SMIs) — release a slow-moving mist that’s easier to inhale deeply.

Each design exists for a reason: to meet different needs, lung capacities, and medication types.

Two Main Types of Asthma Inhalers

Most asthma inhalers fall into two key categories — rescue inhalers and controller inhalers.

Both are essential but serve distinct functions.

1. Rescue (Quick-Relief) Inhalers

Rescue inhalers contain short-acting bronchodilators, like albuterol, that relax the muscles around the airways. They work within minutes to relieve coughing, wheezing, or breathlessness during an asthma flare.

They’re sometimes referred to as “reliever” or “emergency” inhalers — and for good reason. However, relying on them too often can signal that long-term asthma control isn’t optimal.

Common examples: Ventolin, ProAir, Xopenex.

2. Controller (Maintenance) Inhalers

Controller inhalers are used daily, even when symptoms aren’t present. They typically contain inhaled corticosteroids or long-acting bronchodilators (LABAs), helping to reduce airway inflammation and prevent future attacks.

These inhalers don’t provide instant relief, but they’re crucial for long-term stability.

Common examples: Flovent, Symbicort, Advair.

Combination Inhalers: Bridging Relief and Control

Some inhalers combine both a corticosteroid and a long-acting bronchodilator. These combination inhalers are designed for people whose asthma isn’t well managed by a single medication. They help maintain open airways and reduce inflammation simultaneously, simplifying treatment routines.

Examples include: Breo Ellipta, Dulera, and Symbicort.

Why Inhaler Type Matters

Choosing the right inhaler depends on:

Frequency of symptoms: Do attacks happen weekly, or only during exercise?

Age and technique: Some devices are easier to use than others.

Doctor’s assessment: Spirometry and lung function tests help determine severity and control level.

An inhaler that’s right for one person may be less effective for another. Understanding these differences allows patients to discuss their options more confidently with healthcare providers.

Proper Use: The Overlooked Factor

Even the best inhaler won’t work if it’s used incorrectly.

Common mistakes include:

Not shaking the inhaler before use (for MDIs).

Failing to exhale before inhaling the medicine.

Breathing too fast or too shallowly.

Skipping mouth rinsing after corticosteroid use (which helps prevent irritation or infection).

Health professionals often recommend using spacers or holding chambers to improve medication delivery, especially for children or anyone who struggles with timing the inhale correctly.

Inhaler Maintenance and Expiration

Like any medication, inhalers have shelf lives. Keeping track of expiration dates and cleaning the mouthpiece regularly prevents buildup and ensures proper function. A clogged or expired inhaler may deliver less medication, compromising asthma control.

When to Revisit Your Treatment Plan

Asthma is dynamic — triggers, environments, and even bodies change over time.

You should revisit your inhaler plan if:

You’re using a rescue inhaler more than twice a week.

You wake up at night due to asthma symptoms.

You’ve noticed decreased response from your usual inhaler.

Your doctor recommends stepping up or down your treatment.

Asthma management is not one-size-fits-all; it’s an evolving partnership between patient and provider.