Objective To produce a single ‘growth-chart-style’ blood pressure (BP) chart with clear diagnostic thresholds to assist paediatricians to make prompt and accurate diagnoses of hypertension.

Design The well-established but complex published data on normal BP ranges in prepubertal children were identified and analysed to determine if it was possible to produce a single, user-friendly, colour-coded chart, showing diagnostic hypertension thresholds for systolic and diastolic BP without losing clinically important information.

Results There were sufficient published normative childhood BP data available to define systolic and diastolic BP centiles from term onwards but only sufficient to determine systolic BP centiles from 28 weeks of gestation to term. Up to 13 years of age, it was possible to combine boys’ and girls’ data without loss of precision and to define the threshold between stage 1 and stage 2 (severe) hypertension as the 95th centile +12 mm Hg. This allowed the production of single colour-coded charts for systolic and diastolic BP and to advise on making simple adjustments for the impact of stature on individual children’s results.

Conclusions A simplified, integrated BP chart with colour-coded diagnostic thresholds was produced to assist the prompt diagnosis of hypertension in prepubertal children. This information could be included into a Paediatric Early Warning System score.