High blood pressure, or hypertension, affects an estimated 1.3 billion people worldwide, according to the World Heart Federation, making it the number one risk factor for death globally. The American Heart Association estimates that half of US adults have high blood pressure, with a large proportion blissfully unaware. There are effective treatments, but detecting and monitoring it isn't always a walk in the park - especially if you suffer from white coat syndrome, where your BP spikes the moment a doctor walks in.

I exhibit symptoms of white coat syndrome, so tracking my blood pressure at home throughout the day is essential. An arm cuff isn't exactly convenient for regular checks, so I'm grateful that wearable tech companies are stepping up. Apple recently released its hypertension notifications feature, but I've yet to see any notifications from it, and it doesn't monitor real-time BP. So I tested three popular options over the past month: the YHE BP Doctor Fit, the Samsung Galaxy Watch Ultra, and the Amazfit Cheetah 2 Ultra and Balance 3.

To get accurate results, I sat comfortably in my office chair after clearing my mind and relaxing. I measured my BP with the Garmin Index BP Monitor as the standard, then took readings from each candidate watch on the same wrist in the same position. I repeated this in the morning before work, midday, and at the end of the workday.

The YHE BP Doctor Fit uses an integrated inflatable airbag that mimics a blood pressure cuff. I thought for sure it would be the most accurate, but it regularly measured about 15 mmHg higher on the systolic number, with diastolic within 2 to 4 mmHg. It also had the most inconsistent readings and produced the most errors, requiring multiple sessions to get results.

Samsung's Galaxy Watch Ultra uses a proprietary algorithm calibrated with a monthly arm cuff session. Results were fairly consistent but usually 12 to 14 mmHg higher for systolic and 10 mmHg lower for diastolic - rarely matching the Garmin Index.

Amazfit's watches (I used the Cheetah 2 Ultra and Balance 3) were the surprise winners: always within 2 to 4 mmHg in both systolic and diastolic numbers compared to the Garmin. The catch? They're only cleared for BP monitoring outside the US. (Simply set your Amazfit account location to Brazil, and the feature appears.)

Given that I'm on low-dose BP medication and working to get off it, accurate home monitoring is crucial. The Amazfit watches delivered that accuracy, along with a blistering pace of new models, compelling features, and reasonable prices. I'm hopeful they'll get FDA clearance stateside someday. For now, if you can live with the location workaround, one of these is an easy recommendation.