<p>Blood pressure is the product of a complex interplay between the pumping action of the heart and the resistance capacity of both large and small arteries. These are modulated by several physiological processes, including the autonomic nervous system, renin angiotensin aldosterone system, neurohormonal influences and fluid balance. Dysregulation of one or more of these can lead to hypertension. Consideration of the key concepts underlying the generation and regulation of blood pressure is important to consider when selecting an appropriate antihypertensive agent. This review will outline the main physiological processes contributing to blood pressure and discuss their relevance to the pathophysiology and treatment of primary hypertension in children and young people.</p> Graphical Abstract <p></p>