If you were literally just sitting and making no sudden movements or weren’t stressed, that’s a bit of a worry. They are usually pretty accurate. I’ve seen them measure a big drop in the pulse while someone almost fainted and had been feeling sick.

How tight/loose is your watch on your wrist? When you’re sitting down do you have your arms pressed into armrests or anything? Sometimes the single low/high reading is due to skin contact issues. I get about two lower-40s readings per day usually in between some 70-80 readings. Went to the doctor because everyone on Reddit seemed to doomsday about it, hospital ekg showed nothing and the doctor pretty much said that’s normal for an Apple Watch since any movement that causes contact loss can screw with it. Now I just go through and delete any low anomalous readings at the end of the day.

Hi, please can you tell me how I can view that exact screen on my phone I can’t seem to find it? xx

If its just once , may be got to do with bad grip on the wrist. But if it is continuous readings for a few minutes, you should get it checked. 48 hr is fine at rest, 174 is not.

You can also do an ECG at home and get it reviewed from an app called QALY. That is also pretty accurate and i use it periodically to track ecgs.

I find them VERY accurate. Spent time in cardiac rehab and the RNs would work with me to help check the nodes that were attached to me matched the Apple Watch…on point every time… no joke. On top of that I don’t have a strong a pulse as most men