The recent guideline from the National Institute for Health and Clinical Excellence (NICE) on the clinical management of primary hypertension enables us to provide evidence-based care to patients with high blood pressure (BP). The guideline provides a clear treatment algorithm, starting with A (an ACE inhibitor or angiotensin 2 receptor blocker) or C (a calcium channel blocker), depending on the age of the patient, then combining them if target BP is not reached and then adding in D (a diuretic) if required. This article uses a series of case studies to illustrate diagnosis and treatment based on the new guidelines.