Your fitness tracker might soon be able to tell you that you’re sick before you even notice

Because none of us can resist a fabulous gadget, most of us have some kind of fitness tracker. These handy little devices can track your steps, your sleep, your altitude, and some can even capture your heart rate. And a new study from Stanford University suggests that wearable sensors will tell if you’re sick before you even feel it. Dr. Michael Snyder, director of the Center for Genomics and Personalized Medicine at Stanford, studied 60 people who wore trackers that took 250,000 measurements per day. And what they found was that illness caused deviations in the readings, before the subjects felt sick.

With this wearable technology that isn’t far from what we already have, we might be able to predict that we’re getting sick before we feel it.

The trackers that Dr. Synder created measured things like heart rate, oxygen in the blood, activity, calories burned, sleep patterns, and skin temperature. And they got their data by wearing between one and seven commercially available activity monitors every day. Snyder believes that tracking this kind of data will become more and more common.

He said, “In the future, you will have multiple sensors relaying information to your smartphone, which will become your health dashboard. Alerts will go off with elevated heart rate over your normal level and heart beat abnormalities will be detected — these will enable early detection of disease, perhaps even before you can detect it yourself.

Dr. Snyder was a part of his own study, and last year he accurately predicted that he had Lyme disease.

After recording enough data from each participant to establish a baseline, Dr. Snyder started looking for changes in the normal pattern. For example, when he flew on an airplane, Dr. Snyder noticed that his oxygen levels usually decreased and his heart rate increased at the beginning of the flight. But on one particular flight, he noticed that those readings didn’t go back to normal the way they usually did.

Dr. Snyder thought he was coming down with an illness. When he developed a fever, he thought he might have Lyme disease. He had just traveled to a rural area where he might have gotten a tick bite, and he recognized the symptoms as being consistent with Lyme disease, and he was right. Several other subjects in the study also experienced changes in heart rate and skin temperature before getting sick.

But just because Dr. Snyder accurately predicted his illness, doesn’t mean we should all going around doing that.

Dr. Snyder is a knowledgable scientist, and even with his theory, he still went to a doctor for confirmation. And that’s actually the most important issue when discussing health trackers. Doctors worry that we’ll all start self-diagnosing (more than we already do by searching symptoms on the internet). So all doctors insist that we still seek medical opinions if we think something’s wrong.

But using these kinds of medical sensors while working with a doctor could help doctors better track diseases and their progression. Dr. Karandeep Singh, a medical researcher at the University of Michigan, who wasn’t involved in the study commented on its potential.

He said, "Physiological changes precede the development of symptoms for a variety of illnesses, and being able to detect these changes early may bring patients to attention much earlier when diseases are more readily treatable and potentially curable."

That’s pretty awesome news all around. We already love tracking our activity with our wearables, so being able to track more sounds even better. Plus, we might be able to take better care of ourselves if we can predict illnesses sooner. And that will probably keep all of us happier and healthier.