Ambulatory Blood Pressure Monitoring (ABPM) is a diagnostic tool used to measure blood pressure continuously over a 24-hour period. The patient wears a portable monitor with a cuff that automatically takes blood pressure readings at regular intervals, typically every 15 to 30 minutes. This approach allows for a comprehensive assessment of blood pressure variations throughout daily activities and sleep, providing a more accurate picture of hypertension compared to single readings taken in a clinical setting. ABPM helps in diagnosing hypertension, evaluating treatment effectiveness, and identifying patterns that may not be evident from occasional measurements.