Over the past decade, smartphones have radically changed many aspects of our everyday lives, from banking to shopping to entertainment. Medicine is next. With innovative digital technologies, cloud computing and machine learning, the medicalized smartphone is going to upend every aspect of health care. And the end result will be that you, the patient, are about to take center stage for the first time.

With the smartphone revolution, an increasingly powerful new set of tools—from attachments that can diagnose an ear infection...