One needs to confirm presence of hypertension based on three blood pressure measurements at separate clinical visits.

Normative BP percentiles are based upon data on gender, age, height, and blood pressure measurements from the National Health and Nutrition Examination Survey and other population–based studies.

In a study published in the journal Pediatrics in 2013, the initial BP measurement was normal (below the 90th percentile), pre–hypertensive (systolic or diastolic BP between the 90th or 95th percentile) and hypertensive (systolic or diastolic BP ≥95th percentile) in 82, 13, and 5 percent of children.

At follow–up, subsequent hypertensive measurements were observed in only 4 percent of the 10,848 children who had initial hypertensive values. In the cohort, the overall prevalence of hypertension was 0.3%.