Watches with a blood pressure monitor can provide accurate readings, although this has not been demonstrated in large scale studies. For more accurate and consistent results, it may make sense to choose a watch specifically designed for this purpose, rather than a fitness tracker that includes this feature. Fitness trackers are sensitive to blood pressure monitors and can measure blood pressure on the wrist. The wrist should be at heart level to measure blood pressure more accurately.
The measurement taken on the arm could also be inaccurate or be higher than the measurement taken on the wrist. This is possible because the arteries in the wrist are smaller and shallower. This is how fitness bands measure blood pressure. Some pressure readings may be accurate, but there are certain caveats.
According to the Mayo Clinic, when users wear monitors on the wrist, the wrist and arm should be at heart level for a more accurate reading. Because the arteries in the wrist are narrower and closer to the skin than those in the upper arm, the readings may not be as accurate as those on the monitors in the upper arm. The BP Doctor Pro is one of the first smartwatch devices with medical-level accuracy in measuring blood pressure. By applying the patented oscillometric measurement (the only medical method for measuring blood pressure), BP Doctor Pro can measure your blood pressure accurately.
The results are within ± 10 mmHg of the values of a traditional sphygmomanometer, depending on body condition or mood. Wearable fitness trackers are becoming increasingly popular as people look for ways to monitor their health and fitness.