The fluorescent lights of your primary care clinic hum with a low-grade buzz that seems to amplify the late afternoon fatigue. It’s been a day of back-to-back viral upper respiratory infections and medication refills. You rub your temples and click open the next chart.

Caleb Robinson, a 34-year-old graphic designer, is waiting in Exam Room 2. You know him well; he’s a pleasant guy who usually only comes in when things get rough. Today, he looks tired. There are dark circles under his eyes, and he’s holding his rescue inhaler like a stress ball.

“Doc, I think I need a stronger inhaler,” he says, his voice a bit raspy. “This red one just isn’t cutting it anymore. I’m using it before I work out, when I wake up, and basically whenever I walk up a flight of stairs.”