Can Your Fitness Tracker Warn You’re Getting Sick?

Research shows that using wearable sensor health monitoring in devices like smartwatches and fitness trackers can detect developing problems. 

Wearable high tech devices have quickly grown in popularity in recent years — and no wonder. The latest versions of smartwatches function like small computers and fitness trackers can tell you how far you walk, figure out your best exercise route via GPS, measure your heart rate, and even calculate how much sleep you’re getting.

But Michael Snyder, PhD, professor and chair of genetics at Stanford University, thinks wearable technology can do much more — especially when it comes to health.

"We want to tell when people are healthy and also catch illnesses at their earliest stages," said Snyder, senior author of a study that found wearable devices with biosensors can detect changes in physiology, indicating health problems are developing.

YOU MIGHT ALSO LIKE: Wearables to Fight Allergies

Snyder and colleagues collected nearly 2 billion measurements from 60 people who wore a variety of commercially available activity monitors and smartwatch-type devices. While the research subjects went about their daily lives working, travelling, exercising, and relaxing, over 250,000 measurements were recorded over the course of almost a year — including their weight, heart rate, blood oxygen levels, and skin temperature. The technology also tallied physical activity, as well as sleep, calories burned, and even exposure to x-rays. Periodic lab tests were conducted to check the volunteers’ health status, too.

The study included data from 43 of the research subjects and found deviations from what was normal for an individual often coincided with a person getting sick — whether it was a common cold or something more ominous.

The study raises the possibility of finding a wide range of inflammatory diseases in people who may not have a clue they are getting sick. For example, higher-than-normal readings for heart rate and skin temperature flagged by the wearable sensors correlated with blood tests showing increased levels of C-reactive protein, a marker of inflammation that often indicates infection, autoimmune diseases, cardiovascular disease, or even cancer.

In addition, the wearable devices could also help warn people they are at risk for type 2 diabetes. Using an algorithm that combined how many steps the volunteers took each day and the difference between the research subjects’ heart rate at night and in the day time, the researchers were able to predict which participants likely had insulin resistance, a precursor for type 2 diabetes. Glucose tests showed the predictions were spot on.

Snyder participated in the Stanford research project himself and learned he was in the early stages of a potentially serious illness, thanks to the wearable sensors he wore on a long flight to Norway in 2015.

"I had an elevated heart rate and decreased oxygen at the start of my vacation and knew something was not quite right," Snyder recalled. He was also running a low-grade fever. A doctor visit and lab tests revealed Snyder had a potentially serious infection — Lyme disease. He was able to get quick treatment with antibiotics for the early-stage infection, and his symptoms soon disappeared.

Most people only have their health data collected when they go to their doctor for a checkup or due to an illness. But Snyder predicts in the future, easily wearable sensors will allow health to be monitored continuously for early signs of treatable problems. Consumers have already bought more than 50 million smartwatches and 20 million other fitness monitors, and most could easily be adjusted to directly track health data, according to Snyder.

In the meanwhile, if you are wearing a device that monitors some aspects of your health and you notice your heart rate or other measurements seem out of whack, consider talking to your doctor. A Connecticut woman recently noted an unusually elevated heart rate via her fitness tracker and sought medical help. Her doctor discovered she had developed a life-threatening condition, blood clots in the lungs, and her quick attention to the too-high heart rate recorded by her Fitbit likely saved her life.

YOU MIGHT ALSO LIKE: Our Wearables and Fitness Tracker Section