I find that blood pressure and heart rate readings are quite accurate, but heart rate reading using ECG function alone does not seem to be accurate, it sometimes gives very high reading and sometimes low. It also seems to struggle to measure HR while standing because of increase in HR upon standing (inaccurate reading or poor signal). I have had orthostatic hypertension (BB and HR increase upon standing) post-COVID, so I have to monitor my BB and HR in different positions (resting to sitting upright to standing) and watch out for difference. Unfortunately, this device does not measure HR accurately through ECG while standing. However, I have to be clear that it still measures BB and HR pretty well (both sitting and standing) using the blood pressure option. Moreover, I like that it is very compact and mobile and has an excellent app that visualize your results and provides greater insights of your readings. Excellent for the price, as well, given discount.