Because of the new data on lifetime risk of hypertension and the impressive increase in the risk of cardiovascular complications associated with levels of BP previously considered to be normal, the JNC 7 report has introduced a new classification that includes the term “prehypertension” for those with BPs ranging from 120–139 mmHg systolic and/or 80–89 mmHg diastolic. This new designation is intended to identify those individuals in whom early intervention by adoption of healthy lifestyles could reduce BP, decrease the rate of progression of BP to hypertensive levels with age, or prevent hypertension entirely. Another change in classification from JNC 6 is the combining of stage 2 and stage 3 hypertension into a single stage 2 category. This revision reflects the fact that the approach to the management of the former two groups is similar.
Table 3 provides a classification of BP for adults 18 years and older. The classification is based on the average of two or more properly measured, seated, BP readings on each of two or more office visits. Prehypertension is not a disease category. Rather, it is a designation chosen to identify individuals at high risk of developing hypertension, so that both patients and clinicians are alerted to this risk and encouraged to intervene and prevent or delay the disease from developing. Individuals who are prehypertensive are not candidates for drug therapy based on their level of BP and should be firmly and unambiguously advised to practice lifestyle modification in order to reduce their risk of developing hypertension in the future (see Lifestyle Modifications). Moreover, individuals with prehypertension, who also have diabetes or kidney disease, should be considered candidates for appropriate drug therapy if a trial of lifestyle modification fails to reduce their BP to 130/80 mmHg or less.
This classification does not stratify hypertensive individuals by the presence or absence of risk factors or target organ damage in order to make different treatment recommendations, should either or both be present. JNC 7 suggests that all people with hypertension (stages 1 and 2) be treated. The treatment goal for individuals with hypertension and no other compelling conditions is <140/90 mmHg (see Compelling Indications). The goal for individuals with prehypertension and no compelling indications is to lower BP to normal levels with lifestyle changes, and prevent the progressive rise in BP using the recommended lifestyle modifications (see Lifestyle Modifications).