At least one sensor in a wearable device worn by a user may be configured to detect at least one of an electrocardiogram (ECG) signal and arterial pulse (or photoplethysmogram (PPG)) signal. At least one processing circuit may process the ECG signal, the pulse/PPG signal, or both to determine at least one of a pulse transit time (PTT) and pulse arrival time (PAT). The at least one processing circuit may determine a blood pressure (BP) of the user from the PTT, the PAT, or both.
