Heart rate working on one arm, but not the other

[SunsetRunner]

Hi, folks.

Got my first FitBit and chose a Sense (although it now seems like I was lacking in that department when I made the decision)

I bought it primarily as a heart rate monitor, but it only seems to recognise and record my heart rate when worn on my right wrist.

As a right-handed person, I like wearing my watch on my left wrist - but it just can’t find my heart rate.

Any suggestions? Very tempted to return it and try an alternative.

[Converse]

in the setting in the app for fitbit set it to your non dominate hand and see if that fix's the issue of it not working on that arm.

[LZeeW · Accepted solution]

Hello @SunsetRunner and welcome to the Help forum.  Do you have a tattoo, scar, birthmark, or anything on your left wrist?  The heart rate sensor gives off light that must be reflected back in order to read your heart rate.

[SunsetRunner]

I’ve switched between both in the app but no luck.

tried it as dominant & non-dominant on my right wrist and both worked.

neither worked on my left wrist.

[SunsetRunner]

Hello! Yeah, I have both arms tattooed, but the left is almost completely blacked out. That’s frustrating if that’s the case. Thanks!

[LZeeW]

@SunsetRunner   Sorry, but that is the case.  This heart rate technology looks for pulsations in very tiny blood vessels just below the skin.  Those blood vessels are in the same layer where tattoo ink is deposited.  So the ink either absorbs the light and none get reflected or the blood vessels are deformed and any reflected information has too much "noise" to give a reading.  All companies that make smartwatches use the same technology.  You might have more luck with a different brand, but don't count on it if your ink is that dark.  A few years ago, this issue got a lot of attention with the Apple watch.  This discussion was known as #Tattoogate.  For those of us who know our physics, this is not an easy issue to fix.

[pdarco]

Hi LZeeW,

the same is happening with my new versa2, I am left handed and prefer to have it on my right arm, I also wear my regular watch on the left whenever go out and yes my right arm does have a tattoo, but the strange thing is that this wasn't happening with my old inspire 2, used to work fine and never skipped a beat.

[LZeeW]

Hello @pdarco and welcome to the Help forum.  Heart rate measurements use a combination of emitter(s) and sensors.  I know that the arrangement is different on the Inspire 2 compared to the Versa 2.  I don’t design this equipment, but it can explain why you can’t get a reading.  Other users with tattoos also notice that they don’t always get readings when using different devices.