Children and adolescents are defined as having high blood pressure or hypertension if their average systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) is at or above the 95th percentile for sex, age, and height. Sex-specific tables by age and height percentiles are used to estimate the SBP and DBP percentiles.
Blood pressure is measured by averaging up to 3 blood pressure readings taken during the physician examination in the NHANES mobile examination center.
Blood pressure has been measured with the mercury sphygmomanometer for many years but with new technologies available, alternative blood pressure devices have taken center stage. The rapid pace of the development of automated sphygmomanometers with improving accuracy and reliability combined with increasing affordability has meant that these devices have now replaced the mercury sphygmomanometer in many settings. A detailed description of the procedures for blood pressure measurement in the NHANES has been published elsewhere.