A:Answer No, there is no fitness tracker made, at any price, that measures blood pressure, as this would be physically impossible.
(Rough) blood oxygen saturation and heart rate are possible simply be shining a light into your arm and measuring the refractiveness of your blood and the skin conductivity of your heart's electrical impulses. A blood pressure requires that you constrict an artery and measure the arterial pressure required for it to overcome a certain level of constriction. That's why every time you've had a blood pressure taken, it did a little arm squeeze.
There are many inexpensive, wrist-mounted automatic blood pressure cuffs for home use out there. But they are all far bulkier than a smart watch because they have to inflate and deflate a cuff around your arm. No smart watch will ever be able to do this. The best you can get for heart monitoring in a smart watch would be the very, very rough (but still clinically useful at times) 2-lead EKG that can detect very mild cardiac arrhythmia such as atrial fibrillation, but this is, again, done through electrical conduction (the "E" in EKG), and blood pressure requires just that - pressure.
Source- I'm a paramedic.
