Metered-Dose Inhaler: How It Works, Common Brands, and What to Watch For

When you need fast relief for asthma or COPD, a metered-dose inhaler, a handheld device that releases a precise puff of medication into the lungs. Also known as a MDI, it’s one of the most common tools for managing breathing problems. Unlike pills or syrups, it sends medicine straight to where it’s needed—your airways—so it works faster and with fewer side effects. But if you don’t use it right, you might as well be spraying the medicine into the air.

Many people think shaking the inhaler and pressing the button is enough. It’s not. The biggest mistake? Not breathing in slowly and deeply right after pressing it. If you puff and then hold your breath for just a second, most of the medicine lands in your mouth or throat, not your lungs. That’s why doctors often recommend a spacer, a tube-like device that attaches to the inhaler to help hold the medicine until you breathe it in. Spacers make a huge difference, especially for kids and older adults. They’re cheap, easy to use, and reduce throat irritation from steroids. Another key player here is the bronchodilator, a type of drug that opens up narrowed airways. Albuterol is the most common one, but others like salmeterol or formoterol are used for longer-term control. Then there are inhaled corticosteroids, anti-inflammatory drugs that prevent swelling in the airways—often combined with bronchodilators in one inhaler for daily use.

You’ll find these combinations in brands like Advair, Symbicort, and Dulera. But not everyone needs them. Some people only need a rescue inhaler for flare-ups. Others need two different devices—one for daily prevention, one for emergencies. Using the wrong one at the wrong time can make symptoms worse. And don’t forget cleaning. A clogged mouthpiece can block the medicine. Rinse your mouth after using steroid inhalers to avoid thrush. Keep track of how many puffs are left—most don’t have counters. And if your inhaler feels different, or you’re using it more than usual, talk to your doctor. These aren’t just devices. They’re critical parts of your health plan.

Below, you’ll find real-world advice from people who’ve dealt with inhaler mistakes, side effects, and how to get the most out of their treatment. Whether you’re new to inhalers or have been using one for years, there’s something here that can help you breathe easier.