Hi all, first-time posting here and just adding my tuppence worth.
I have an Apple watch series 5, bought just over a year ago to monitor my heart rate and to be able to detect AF - which it duly did, resulting in taken off by ambulance to A&E and finally getting some long-overdue treatment started (other attempts to monitor occasionally having failed because my type was intermittent - Paroxysmal).
It links to my iPhone; the Heart Reports app on there will generate a report for any set of given dates which I save as a Pdf, then print off ready for the next appointment with the GP or Cardiologist. My GP loves its functionality and highly approves of the extra scope it gives her when discussing the next steps.
The report can show as much or as little as you want: I have mine set to show average daily heart rate, activity, sleep, plus it also alerts me when there's a too-high or too-low heart rate and time-stamps it. It's a great tool for general information about trends and the like, plus I like the ECG function. This last is how I managed to call for help when I needed it.
It's been a life-saver for me, pure and simple. The medication I'm now on lessens my risk of fatal stroke during an episode which I never knew about - a definite case of ignorance not being bliss.
A bonus of the watch is the fall-detection function, but as J52 has said, be wary of doing things which result in jolts - like playing rugby! - maybe best to take it off. Personally I like the reassurance that if I was on my own and fell help would find me.
Having said all that, I am not joined at the hip to all this, and these days glance at it to see if it's going to rain on the washing soon, or the latest news headline.
The only reason I got this one was a) my tech-savvy son recommended it over all the others at that time and b) it would just work seamlessly with my iPhone. If you don't have that brand of phone, I'm guessing there will be other watches/monitors out there now which will probably do as good a job, and cheaper . Hope that helps.