I walked into my primary care doctor’s office the other day. I’m still young and healthy and a doctor, so making a doctor’s appointment is a rare event. As with most patients, it was symptoms that motivated me. I’m having a common, yet annoying problem: PVCs or premature ventricular contractions. I’ve had them on and off for a while, but now every time I push to my limit when exercising or double my espresso, they come back.

“Do you have them right now?” my doc asked me. “No. Just had them yesterday, though,” I replied. Dr. A is about my age and perhaps in even better shape than I am. He’s certainly smarter than I. Tall and athletic, he doesn’t wear a lab coat but is always immaculately dressed in a button-down shirt and light sweater. He walks from around his standing desk and hands me an iPhone cover. “Why don’t you try this?” Being the director of innovation, I recognized the device: It was a heart monitor. “Just download the app and track your EKG when you get symptoms,” he said.

I turned it over in my hands. It’s flimsier than I remembered from tech conferences. It’s even too small to fit on my iPhone 6+, although it doesn’t technically have to be on the phone to work. When I got home I downloaded the app and uploaded my first tracing. While right next to my phone, I gently touched the two sensors with my fingers. My tracing appeared on the screen. Wow, those are PQRS waves. (Indeed, I was a intern, too, once). The app requires that you submit the first recording for review before you can use it to verify that the tracing is normal.

The next morning, I hit the bike with everything I had, driving my heart rate to more than 170. (150 is working hard, 160 is painful, 170 is unsustainable for me. Sure enough, my PVCs returned later that day. Later that night, they were driving me crazy. I got out of bed and grabbed my phone. There, at 2 a.m., the glow of my iPhone lighting my bedroom, I could see my EKG: 1,2,3, PVC, 1,2,3, PVC. Wow! This is cool.

As the innovation director, most of the devices I review are from the viewpoint of a physician. This was different. I was clearly the patient in this story, and the device was meant to help me.

We talk about how digital medicine empowers our patients, and I suppose this is the idea. I now have access to diagnostic tools that ordinarily only my doctor would have. Yet, even though I clearly had PVCs this time, the app sends me back the same note as the first time I used it: “Normal EKG.” That’s true, technically. However, it’s easy for even a dermatologist to see that this tracing was different from the first.

I knew that quadrigeminy was a common and benign tracing, but if I wasn’t a physician (or hadn’t been trained by a great upper-level resident as an intern), then I might have been too anxious to fall back asleep.

Elizabeth Holmes in a recent Wall Street Journal article advocated for patients to be able to choose their own blood tests (and someday check their own blood, using her device, one presumes). Health care technology conferences abound with devices that promise to put the power of diagnostics in patients’ hands. But, as we all know, getting data is the easy part. It’s interpreting data – that’s why docs get the big bucks.

We also understand that often the best test is no test at all. If we randomly sampled EKGs from a population of everyone, we might find a few interesting tracings, most of which would have no meaningful consequences. Except if you’re a patient and your EKG has a funny blip on your at-home EKG device, or your iPhone dermatology app incorrectly reports a seborrheic keratosis as a possible melanoma. In such cases, these technologies have not empowered the user; rather, they’ve created needless anxiety, none of which existed before. The result is often more work for us physicians who must now spend time explaining why the patient’s finding is not important, and worse, might end up ordering more (real) tests to disconfirm what the at-home home test found.

Later, I brought my iPhone to my follow-up appointment and shared the tracings with my primary care doctor. “Looks like PVCs,” he confirmed, “and it looks normal.” But I already knew that.

Dr. Benabio is a partner physician in the department of dermatology of the Southern California Permanente Group in San Diego, and a volunteer clinical assistant professor at the University of California, San Diego. Dr. Benabio is @dermdoc on Twitter.

Doctor, monitor thyself: The promise and perils of self-monitoring apps