Ambulatory blood pressure monitoring (ABPM) is a crucial tool for diagnosing primary and secondary hypertension, predicting cardiovascular disease and mortality, and identifying white-coat and masked subtypes. It provides a 24-hour account of a patient's state, with a diagnostic threshold of ≥130/80 mmHg over 24 hours. ABPM offers better prognosis of hypertension-mediated organ damage, is more sensitive to CV outcomes, and can provide stronger prognostic evidence.