Have you ever stopped to think about how often you check your phone just to see how many steps you’ve taken? Or whether you slept enough last night? Or if your heart’s beating a little faster than it should? These days, your wrist might know more about you than your doctor. And while that sounds like the opening line of a sci-fi novel, it’s not. It’s the everyday magic of smartwatches—and they’re quietly changing the way we take care of ourselves.