Blood pressure normal? Maybe now it isn’t.

This spring the National Institutes of Health revised the guidelines for prevention and treatment of high blood pressure (hypertension) for the first time since 1997. The changes included a new definition of "normal" blood pressure. This meant that 45 million Americans who had gone to sleep with normal blood pressure woke up with higher-than-healthy blood pressure. Here are some of the highlights:

  • Normal is now not. What was classified as normal or high-normal blood pressure (a systolic pressure of 120-139 mm Hg and diastolic pressure of 80-89 mm Hg) is now categorized as prehypertension (see chart).

It's a little strange. All of a sudden, the experts are telling millions of people who thought they were healthy that they now have this condition called prehypertension. But the idea is to get Americans and their doctors to take action before the blood pressure climbs any higher - and into the range where the risks of heart disease, stroke, and other problems are pronounced.

In the prehypertensive range, taking action does not mean taking pills. It means, for example, regular aerobic activity, such as 30 minutes of brisk walking several days per week. That kind of exercise can lower your blood pressure by 4-9 mm Hg. If you're overweight, losing about 22 pounds is "worth" a 5-20 mm Hg subtraction in systolic pressure. Limit your sodium intake to 2.4 grams daily and the benefit is a 2-8 mm Hg reduction.

  • Procrastination doesn't pay. You don't want to put off doing something until your reading is 140/90, the beginning of what's now called stage 1 hypertension. Several studies have shown that your cardiovascular risk starts climbing at 115/75 mm Hg - not 140/90. And starting at 115/75, the risk doubles for each 20 mm Hg increase in the systolic pressure and each 10 mm Hg increase in the diastolic pressure.
  • Keep your eye on the top number. The guidelines re-emphasize that in most people over age 50, systolic is more important than diastolic blood pressure. What's more, if you get your systolic pressure into a healthy range, your diastolic pressure will probably get there, too.
  • Start with a diuretic. If your blood pressure is over 140/90, the guidelines say you should be taking a blood pressure medication and that initially it should probably be a thiazide-type diuretic (chlorothiazide, hydrochlorothiazide, others). At first, these drugs increase urination, but usually the body adjusts so levels return to normal in a few weeks.

The diuretic part of this recommendation is controversial. Dissenting experts cite studies that show some patients do better starting on other drugs, such as ACE inhibitors. But the reality is that many people are going to need to take two drugs - a diuretic and something else - anyway. This is particularly true if you have another health problem, such as diabetes, kidney disease, or heart disease.

  • The best medication? Motivation. It is hard to stay motivated about high blood pressure. It doesn't have symptoms. It's not a new, exciting problem.

The guidelines lecture physicians about building trust with empathy. But this is a two-way street. As the patient, you can ask your doctor questions, get tips about diet and exercise, and mention any side effects and other troubles you might be having with your medications.

What category are you in?

These are the categories in updated blood pressure guidelines from the National Institutes of Health.

Systolic (top number)

Diastolic (bottom number)

What you should do


Less than 120

Used to be <130


Less than 80

Used to be <85

Keep up the good work!


Blood pressure in this category used to be considered high-normal.




Change health habits. If you're heavy, lose weight. Reduce salt in your diet. Eat more fruits and vegetables and get more exercise. Moderate alcohol consumption might help, too. Medications are not recommended at this stage.

Stage 1 hypertension




Change health habits and take a blood pressure medication, probably starting with a diuretic. If you have another health problem (diabetes, angina, kidney disease, etc.) then a different drug (beta blocker, ACE inhibitor, etc.) is probably necessary.

Stage 2 hypertension

The Stage 3 hypertension category has been eliminated.

160 and higher

Used to be



100 and higher

Used to be 100-109

Change health habits and take two blood pressure medications, usually a diuretic and something else.

Source: Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure,