Health Trackers Provide Lots of Information with Marginal Benefit

For many people, the smart “watch” on their wrist isn’t for telling time. Today’s wearable gadgets and gizmos have the capacity to “watch” nearly every aspect of our health: heart rate and rhythm, breathing patterns, sleep patterns, hydration, blood oxygen levels, blood pressure, temperature, menstrual cycles, stress levels, steps and distance traveled, and more.

An ad for one such device boldly declares: “The future of health is on your wrist.”

UNC Health cardiologist Christopher Kelly, MD, isn’t so sure.

“These devices satisfy people’s general curiosity about their health,” he says, “but the majority of people don’t need them for any medical reason. Not yet, at least, with the devices available now.”

Wearables Track Vitals but Only Rarely Catch Problems

While he doesn’t generally recommend that his patients buy these devices, Dr. Kelly notes that they can occasionally reveal important information.

For example, some of the devices that monitor heart rate can also capture an electrocardiogram (EKG), which records electrical signals from the heart. This information can sometimes expedite a medical evaluation.

“The Apple Watch has helped me diagnose atrial fibrillation (irregular heartbeats) or early heartbeats called PVCs (premature ventricular contractions),” Dr. Kelly says. “Unfortunately, these devices do generate a lot of false positives, too, so don’t freak out just because your watch says you might have atrial fibrillation, as you most likely don’t. Make sure you review the recordings with your doctor.”

A cardiologist will take this information, do additional testing and monitoring, and determine what, if any, treatment is needed.

When Monitoring Blood Pressure, Use a Cuff

Some watches are capable of measuring blood pressure, but Dr. Kelly says the readings are not yet as accurate or reliable as an upper arm blood pressure cuff. Home blood pressure monitors are highly recommended for people who have been diagnosed with high blood pressure, and routine monitoring can be very useful in stabilizing blood pressure.

It’s important to have a reliable device, of course. Dr. Kelly recommends making sure the monitor you use at home has been tested and validated for clinical accuracy.

“If you’re getting different readings at home than you get in the (doctor’s) office, bring your cuff to your next visit,” he says. “Sometimes we do find that a cuff has become inaccurate, and it’s time for a new one.”

Who Needs a Health Tracking Wearable Device?

Health trackers can be useful for people seeking a specific goal: to get a certain number of steps a day, to track hours slept, or to know when they’re most fertile, for example. That doesn’t mean the information is always 100 percent accurate, but it can provide data for improving one’s health.

People with chronic medical conditions or unexplained symptoms may benefit from a wearable device, but they should talk to their doctor about the best way to do it, whether through a device available on the consumer market or one that requires a doctor’s prescription or oversight.

“Certainly, if you have an established diagnosis, home devices can be very helpful,” Dr. Kelly says. “If you have AFib, diabetes or high blood pressure, home devices can be essential. But for healthy people without symptoms, their utility Is more questionable.”

In fact, monitoring every blip in your vital signs can impact your mental health, even though, physically, you are completely within normal ranges.

“People who have health anxiety in general are not well-served by these devices,” Dr. Kelly says.

And sometimes the device readings can distract people from more critical health concerns, he adds. “They’ll be worried about their heart rate when it would be more useful to focus on their weight, for example.”

The most important thing to remember about these wearable devices is that they are not always accurate.

“False positives can occur,” Dr. Kelly says. “Just because your device tells you there’s a problem doesn’t mean there really is one. The best thing to do, if you have any concerns, is talk to your doctor.”


If you have health questions—with or without data from a monitoring device—talk to your doctor. If you don’t have a doctor, find one near you.