From the day we're born, we know how to breathe correctly. That means letting the diaphragm—the large, thin muscle just below the rib cage—do the work of drawing air into the lungs and letting it out.

That familiar tightness in your chest. The wheeze that seems to announce itself at the most inconvenient moments. The inhaler you clutch like a lifeline. Living with asthma can feel like your lungs ...