Prehypertension

Prehypertension, also known as high normal blood pressure and borderline hypertensive (BH), is a medical classification for cases where a person's blood pressure is elevated above optimal or normal, but not to the level considered hypertension (high blood pressure). Prehypertension is now referred to as "elevated blood pressure" by the American College of Cardiology (ACC) and the American Heart Association (AHA). The ACC/AHA define elevated blood pressure as readings with a systolic pressure from 120 to 129 mm Hg and a diastolic pressure under 80 mm Hg, and the European Society of Cardiology and European Society of Hypertension (ESC/ESH) define "high normal blood pressure" as readings with a systolic pressure from 130 to 139 mm Hg and a diastolic pressure 85-89 mm Hg. Readings greater than or equal to 130/80 mm Hg are considered hypertension by ACC/AHA and if greater than or equal to 140/90 mm Hg by ESC/ESH. Classification of blood pressure is based upon two or more readings at two or more separate occasions, and compared to out-of-office blood pressure readings if possible. Prehypertension is often asymptomatic (without symptoms) at the time of diagnosis. Only extremely elevated blood pressure (malignant hypertension) can, in rare cases, cause headaches, visual changes, fatigue, or dizziness, but these are nonspecific symptoms which can occur with many other conditions. Thus, blood pressures above normal can go undiagnosed for a long period of time. Elevated blood pressure develops gradually over many years usually without a specific identifiable cause. However, possible medical causes, such as medications, kidney disease, adrenal problems or thyroid problems, must first be excluded. High blood pressure that develops over time without a specific cause is considered benign or essential hypertension. Blood pressure also tends to increase as a person ages. To lower the risk of prehypertension progressing to hypertension, modification of lifestyle or behaviors is necessary.