National guidelines place your blood pressure into one of three categories: normal, prehypertensive, or hypertensive . Normal blood pressure is considered to be less than 120/80 mm Hg. If your blood pressure is equal to or higher than this for two or more readings on different days, you are classi?ed as either prehypertensive or hypertensive. The guidelines, based on the impact of high blood pressure, are aimed at getting you and your doctor started as soon as possible to bring your blood pressure down to healthy levels.

Prehypertension

If you have prehypertension (with readings consistently 120/80 or higher but below 140/90), you are in a group that used to be called high normal. Almost one-third of the U.S. adult population now falls into the prehypertensive category. The most recent guidelines identify this range as a warning zone, because people in it are considerably more likely to develop true hypertension later in life. The designation of “prehypertension” re?ects evidence showing that the risk of heart disease actually begins to climb at readings above 115/75 mm Hg. From that level, every increase of 20/10 mm Hg doubles the risk of death from heart disease. Changing to a healthy lifestyle is the only way to prevent this progression into high blood pressure.
If you are in the prehypertensive category, you have a good reason to get motivated to start managing your blood pressure immediately through nondrug treatment. Even though you do not have high blood pressure, you can start making changes in your lifestyle that will bring your readings down to a lower, healthier level without medication; see pages 46–47. Lifestyle changes alone are likely to help you at this early stage. You and your doctor can start talking about setting priorities and taking de?nite steps to form some new habits.
Start with your eating habits. Eat 8 or more servings of fruits and vegetables each day and less fat and saturated fat. Limit salt intake to less than 1,500 mg per day, or about 3?5 of a teaspoon of salt. If you are overweight, losing weight can be important. The bene?ts of weight reduction start early, with a loss of as little as 10 to 15 pounds, because with every 3 pounds you lose, there is an average corresponding drop of about 2 mm Hg in your systolic pressure. Build just 30 minutes of exer- cise into your schedule, at least ?ve days a week. Limit your alcohol intake to no more than one drink per day for women and two drinks for men (whether hard liquor, wine, or beer). These changes may not seem easy at ?rst, but they will pay big dividends if they mean you will not have to take medications.

Systolic Hypertension

The guidelines also say that systolic pressure (the top number) of more than 140 mm Hg should be treated regardless of the diastolic level (bottom number). Either your systolic or your diastolic number—or both—may be elevated. As you get older, your diastolic pressure usually decreases and the systolic pressure begins to rise.
If only your systolic reading is high and your diastolic reading is nor- mal, you have the most common form of high blood pressure. It is called isolated systolic hypertension, and new guidelines emphasize its importance. Treating isolated systolic hypertension early, with lifestyle changes and medications if necessary, reduces the future risk of devel- oping heart disease and stroke. For example, with each reduction of 5 mm Hg in your systolic blood pressure, death from stroke is reduced about 14 percent and from heart disease by 9 percent. The potential impact on your quality of life is enormous.