The Apple Watch Is Now the Control Center for Your Health

THIS WEEK AT Apple’s Worldwide Developers Conference, Apple executive Kevin Lynch announced multiple updates to WatchOS, the operating system that powers the company’s smartwatch. (Voice memos, a calculator, streaming audio, oh my!) But the most telling features were the new additions to the watch’s suite of health-monitoring tools.

Beginning this fall, Apple Watch will track your activity trends over time, help protect your hearing by alerting you to harmful levels of ambient noise, and allow users to track their menstrual cycles. Individually, these improvements might look small or trivial. But given the...