Hypertension is characterised by chronic elevation of blood pressure and affects 20 to 30% of the population worldwide [1]. Hypertension contributes significantly to the global burden of cardiovascular morbidity and mortality. A recent study by Lawes et al. [2] concluded that 13.5% of premature deaths and 54% of stroke and 47% of ischaemic heart disease worldwide are attributable to high blood pressure. Alarmingly, about 80% of the attributable burden occurred in low-income and middle-income economies, and over half occurred in people aged 45 to 69 years. Blood pressure is a continuous, quantitative trait whereas the dichotomous definition of hypertension (i.e. blood pressure above a certain threshold) is to some degree arbitrary and has been modified with expanding knowledge over the years. This has been acknowledged by recent guidelines where borderline or pre-hypertension states have been introduced and recommendations for blood pressure cut-offs and targets are dependent on comorbidities such as diabetes or renal disease [3] and [4]. Blood pressure in the upper range of normal is also associated with increased cardiovascular morbidity and mortality. Only half of the burden in the study by Lawes et al. [2] was in people with hypertension, whereas the remainder was in subjects with lesser degrees of high blood pressure (≥ 115 mmHg but < 140 mmHg systolic). It appears that there is a continuous relationship between blood pressure and cardiovascular risk without evidence of a threshold down to at least 115/75 mm Hg [5].