High blood pressure is called a silent killer for a reason. Symptoms are rarely obvious, but uncontrolled high blood pressure can increase the risk of heart disease and stroke, two leading causes of death for people in the United States. Nearly one out of two adults in the U.S. has high blood pressure, but many don’t know they have it. Fitbit is now one month into its ongoing blood-pressure study for wristworn wearables. Find out more about the Fitbit Sense Blood Pressure feature below.

Checking your blood pressure isn’t always easy, especially if people don’t have a blood pressure cuff at home and only go to the doctor’s office once or twice a year. And because blood pressure can fluctuate for a variety of reasons, ideally people need to repeat this process at the same time over a period of months. So, how can we make it easier for people to monitor their blood pressure?

Fitbit is exploring whether Pulse Arrival Time (PAT) can be used to track blood pressure on the wrist.

PAT measures the time taken from a heartbeat in the chest to reach a pulse in the wrist. The longer the time-taken, the higher or lower the blood pressure.

But PAT is not an easy metric to measure. The body jiggles around a lot, arms wave about, and measurements last a fraction of a second. It will be interesting to see the final results of the study. Consumers worldwide, young or old, definitely have a high interest in blood pressure tracking. For example, a recent survey from the UX division found it to be a top-10 feature of high importance in Europe. The full Strategy Analytics survey can be seen here.

Previous Fitbit Labs research has found a correlation between PAT and blood pressure, but the correlation was not strong enough to predict blood pressure. These investigations were limited to either small data sets or specific environments, like an intensive care unit. Fitbit Labs also found a correlation between PAT and blood pressure in a small, 3-week internal study. The new study will extend this work to a broader population in order to learn more about how PAT measurements change under a variety of conditions.

“If high blood pressure was easier to measure, people could manage it earlier, which might help avoid preventable deaths from heart disease and stroke,” said Shelten Yuen, Principal Scientist at Fitbit, who is leading this work “It’s a hard scientific challenge, and a lot of work remains to be done to understand the best way to do this, but we have a history of advancing technology to make previously inaccessible health metrics available to Fitbit users from their wrist, so it’s a challenge we’re very passionate about solving.”

Having easy access to blood pressure readings is important for people with hypertension, so, assuming we can correlate PAT and blood pressure, being able to track PAT with a Fitbit device might give people more power to manage their condition in between doctor visits.

Advancing the Future of Wearables fitbit blood pressure

Fitbit’s mission has always been to make everyone in the world healthier by making health more accessible. Fitbit pioneered the 10,000-step phenomenon and since then has introduced many other innovations, including heart rate monitoring on the wrist with our Pure Pulse technology, which has continued to advance over the years. With the Fitbit ECG App, we’re assessing users’ heart rhythms for signs of AFib, an irregular heart rhythm that increases the risk of serious heart conditions like stroke. These innovations, as well as our newest and most advanced sensors, are not only the foundation for many important health features but they can also be used to explore novel technologies, like measuring PAT in this new study. Fitbit senses Blood Pressure