Hypertension is one of the leading contributors to global cardiovascular morbidity and mortality. Recent updates to major international guidelines have introduced changes in diagnostic thresholds, risk stratification, and treatment recommendations aimed at earlier detection and improved outcomes. This review summarises recent developments in the diagnosis and management of hypertension, comparing key recommendations from the American Heart Association (AHA)/American College of Cardiology (ACC), the European Society of Cardiology (ESC) and European Society of Hypertension (ESH), and the UK National Institute for Health and Care Excellence (NICE). Particular emphasis is placed on differences in diagnostic criteria, blood pressure targets, and evolving pharmacological and non-pharmacological management strategies. Updated guidelines increasingly promote out-of-office blood pressure monitoring and individualised treatment based on overall cardiovascular risk, comorbidities, and target-organ damage. Despite greater consensus on risk-based management, important regional differences remain, including the lower diagnostic threshold adopted in the United States and variation in treatment targets. Implementation in clinical practice continues to present challenges, as access to ambulatory blood pressure monitoring, healthcare resources, and patient adherence may limit uptake of guideline recommendations.