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 or track heart rhythms to an app that can monitor mental health—can reduce our use of doctors, cut costs, speed up the pace of care and give more power to patients. Digital avatars won’t replace physicians: You will still be seeing doctors, but the relationship will ultimately be radically altered. (I consult for several companies on many of the issues discussed here.)

All of this raises serious issues about hacking and personal privacy that haven’t yet been addressed—and the accuracy of all of these tools needs to be tested. People are also right to worry that the patient-doctor relationship could be eroded, diminishing the human touch in medicine. But the transformation is already under way.

Let’s say you have a rash that you need examined. Today, you can snap a picture of it with your smartphone and download an app to process the image. Within minutes, a dedicated computer algorithm can text you your diagnosis. That message could include next steps, such as recommending a topical ointment or a visit to a dermatologist for further assessment.

Smartphones already can be used to take blood-pressure readings or even do an electrocardiogram. ECG apps have been approved by the U.S. Food and Drug Administration for consumers and validated in many clinical studies. The apps’ data are immediately analyzed, graphed, displayed on-screen updated with new measurements, stored and (at an individual’s discretion) shared. I thought I’d seen it all in my decadeslong practice as a cardiologist, but recently, for the first time, I had an ECG emailed to me by a patient, with the subject line, “I’m in atrial fib, now what do I do?” I immediately knew that the world had changed. The patient’s phone hadn’t just recorded the data; it had interpreted it.