The two blood pressure numbers obtained when a BP reading is taken conveys significant information about hypertensive (ie high blood pressure) in relation to the past, present and future, and behooves understanding from a perspective of using that information for establishing health literacy and achieving patient engagement in the area of ​​hypertension management.

The most important instantaneous information that blood pressure numbers reveal about a person with established hypertension is, whether or not the blood pressure is well controlled. If the BP is 140/90 or greater but there is no record of previous elevated readings of that magnitude or greater, a diagnosis of hypertension can not be made without that initial reading is extremely high, or additional information other than BP readings, is available to support a conclusion the person has pre-existing hypertension which has just not been officially diagnosed.

Additional information that justifies the conclusion that currently recorded elevated blood pressure numbers are indicative of pre-existing hypertension is that which reveals evidence of complications of long-standing BP elevation. Those complications are damage to the blood vessels of the retinae, thickening of the heart muscle, and abnormalities of kidney function, in the absence of other diseases to explain the abnormalities. Damage to the blood vessels of the retinae can be visualized by a primary care doctor with an instrument known as an ophthalmoscope, during a physical examination. Thickening of the heart muscle oftentimes shows up on an EKG. Abnormalities of kidney function can otentimes be detected by performing BUN and creatinine measurements on a sample of blood. Therefore, a dilemma of deciding whether someone has hypertension based on a single initial elevation of the blood pressure numbers of 140/90 or greater can oftentimes be solved with the joint usage of a current BP reading and the additional supporting information.

The future information that contemporary blood pressure numbers convey about hypertension is based on the progressive rise in BP and the increased frequency of hypertension with aging. The age-related rise in blood pressure is continuous through varying age brackets but plateaus in the 80th and 90th decades. The increase in the incidence of hypertension with aging occurs in all ethnic groups with some variation within different groups and a somewhat greater rise among man compared to women. The third HHANES survey reported an age-adjusted prevalence of hypertension of 3.3%, 13.2%, 22%, 37.5%, and 51% in Caucasian man in the 18-29-year-old, 30-39-year-old, 40 -49-year-old, 50-59-year-old, and 60-74-year-old age groups respectively. Another medical study concluded that the incidence of hypertensive increased by 5% for every 10 years of aging. Given these facts, knowledge of one's blood pressure numbers and age at the time of a current BP measurement are fairly good indicators of whether not hypertension will develop in the future, considering life expectancy.