Blood pressure norms and definition of hypertension in children

Prior to the 1970s, measurement of blood pressure was not a standard practice in asymptomatic healthy children. Detection of high blood pressure in children occurred when blood pressure was measured in symptomatic and clinically ill children. In the absence of reference data on blood pressure levels in healthy children, adult criteria were used. Early preliminary data on blood pressure levels in healthy children indicated that the normal range of blood pressure was considerably lower than in adults. It was also recognized that there was progressive increase in blood pressure levels in healthy children that corresponded to childhood growth and development. Subsequently, several large observational studies were conducted on healthy children and adolescents. These studies applied uniform methods in blood pressure measurement along with growth measures of height and weight. Data from these studies have been combined and analyzed to determine the normal distribution of blood pressure levels in healthy children and adolescents. The resulting normal blood pressure range in healthy children from 1 to 17 years of age has become the blood pressure norms on which current definitions of hypertension and prehypertension in children and adolescents are based.