Sharon Viera has what many would consider to be an enviable blood pressure: 118/76.

But today, she wonders.

“ Now what do I do when I go to the doctor's and it's 122 over 80?” said Viera, activities director at Christopher Heights in Attleboro. “ Will I be put on medication for high blood pressure? I don't want to be put on medication if I don't need it.”

Barbara Sheehan, a resident seated nearby in her wheelchair, has her own take on things.

“ It could give you high blood pressure,” she said wryly, “ just thinking about it.”

The National Heart, Lung, and Blood Institute has got your number(s) — and they may add up to big lifestyle changes for you.

Overnight this week, a shift in federal guidelines on what is considered normal for blood pressure shifted 45 million adults in this country — 22 percent of the population — into a new category called “ prehypertensive” or not quite normal.

“ Two days ago at 140 over 90 I would have said, `You don't have blood pressure problems,”' said Dr. Bruce Phillips, a family practitioner in Plainville. “ This is now raising the stakes a bit for the 120 to 140 and 80 to 90 categories, saying you folks are actually at risk.”

Phillips said he has received a couple of inquiries from patients and he sees benefits in the new guidelines.

“ I think the big impact is that people are really going to be wondering what their blood pressure is and what can they do to keep themselves healthiest,” said Phillips. “ The main point, I think, is that most of us, if we want to live a long healthy life free of heart disease and strokes, we need to be living differently than many of us are living now. None of this is rocket science. But I hope this is one more thing that highlights for people what they need to do.”

And what they ought to do, he said, is lose excess weight, get active, limit alcoholic beverages, cut back on salt, and quit smoking. These are the same recommendations issued this week by the NHLBI to accompany its report advising that blood pressure levels once considered normal may actually be risky — or potentially so.

Now “ normal” is anything below 120 over 80.

High is still considered 140 over 90 or more.

Dr. Joseph DiCola, a cardiologist with offices in Attleboro, cautioned that blood pressure is just one measure of health.

“ It is only a piece of the puzzle,” DiCola said. There are other considerations, he said, such as cholesterol levels and pre-existing vascular disease.

“ The emphasis is really on that in-between group everyone falls into,” he said. “ It's the same recommendation — fight weight, exercise. If you do the simple things that have been around for 30, 40 years, that's the recommendation. Doctors are trying to be a little more aggressive. There's a consensus to be more aggressive, especially when treating diabetics.”

He said a host of new blood pressure monitors, including those that can be used in the home, can help augment visits to the doctor.

Nancy Thomas, director of news media relations for the northeast affiliate of the American Red Cross, said the new changes will eventually be reflected in agency literature.

“ We have heard that everything will be revised,” she said. “ This new category of `prehypertension' will be in the new literature. I imagine we will do reprints of the article in the Journal (of the American Medical Association) and we will encourage people to talk to their physicians.”

AHA, she said, will also be providing more education to the public and to professionals.

“ Blood pressure levels are really going up in this country,” said Thomas. “ They're not taking medications. Are they getting screened, do they have health insurance? There is non-compliance. The elderly take their medication for three weeks, and on the fourth week they buy food.”

Part of the problem, she said, is the fact that high blood pressure — often called the “ silent killer” — is painless, so no difference is felt when people stop taking medication. But quietly, the damage takes place.

Hypertension is a major risk factor for heart disease and the chief risk factor for stroke and heart failure, and also can lead to kidney damage, according to the medical community. It affects about 50 million Americans or one in four adults.

While people tend to think of hypertension as a stress-related disease, reports the AHA's national Web site, doctors do not — except in rare cases — really know what causes it. Fifty million Americans have the condition; about half are women.

Blood pressure, as explained by the AHA, is recorded as two numbers:

E The higher (systolic) number represents the pressure while the heart is beating.

E The lower (diastolic) number represents the pressure when the heart is resting between beats.

The systolic pressure is always stated first. For example: 122/76 represents systolic, 122, diastolic, 76.

“ Ten years ago we thought if your cholesterol was under 260 that was great,” said Phillips. “ Now we know it should be under 200. Making that awareness has forced the whole population to move its cholesterol down.”

The new guidelines will give consumers something to shoot at while making lifestyle changes, said Attleboro's DiCola.

“ You can have goals,” he said. “ You might not always get there.”

For complete details visit www.nhlbi.nih.gov/guidelines/hypertension/index.htm

BETSY SHEA-TAYLOR can be reached at 508-236-0439 or at btaylor(at)(at)thesunchronicle.com.