Sarah Hills was worried about her heart.

Her Oura Ring, a wearable device that tracks users' biometric data, including body temperature, heart rate and blood oxygen levels, was telling her something might be off.

The ring provides some of its data in the form of scores, like a "readiness" score that uses "sleep quality, body signals, and activity levels to show how prepared you are to take on the day," according to Oura. Since receiving the ring as a Christmas gift, Ms. Hills had begun to compulsively check her stats. If her scores weren't good, the 22-year-old said, she would ruminate.

When her stats wobbled this year, she tried to see a doctor. When she couldn't get an appointment soon enough, Ms. Hills, a recent graduate of Providence College, and a friend drove to a pharmacy where she spent $50 on an at-home blood pressure cuff and monitor to put her mind at ease.

"At that point I was, like, 'Oh my gosh, this thing is literally destroying my mind,'" she said.

Eventually, Ms. Hills was able to see a doctor who told her she was healthy. The doctor did have one recommendation: Consider ditching the ring.

In the eternal human quest to know thyself, it's tempting to seize on every bit of information we can glean. If you could know, for instance, not just that you slept 6.5 hours last night but also that 12 percent of those hours were spent in REM sleep and that your overall "sleep efficiency" — time asleep versus time awake — was 85 percent, as many pieces of wearable tech can tell you, why wouldn't you?

At least that's the attitude of many people in our age of the quantified self, in which collecting sheaves of data about our bodies every day seems to hold the promise of bringing about a happier, healthier life. But what if all of that data is also heightening our stress? Is there a metric for that?

While some Oura users say they enjoy the ring as a screen-free way to keep tabs on their bodies, several Oura owners, including Ms. Hills, described feeling increasingly anxious after using their devices. Rather than helping them feel more in control of their wellness, the data only made them fixate on potential — and often nonexistent — problems.