Controlling Your Blood Pressure Archive

ARCHIVED CONTENT: As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date each article was posted or last reviewed. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. 

Look for the silver lining...

Buddy DeSylva's upbeat lyrics to Jerome Kern's lovely tune provide an appealing call to a positive outlook on life, even in the face of adversity. Indeed, a cheerful disposition can help you get through the tough patches that cloud every life, but do people who see the glass half-full also enjoy better health than gloomy types who see it half-empty?

ARCHIVED CONTENT: As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date each article was posted or last reviewed. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. 

Dr. Scipione Riva-Rocci started it all in 1896, when he perfected the sphygmomanometer, or blood pressure cuff. As doctors took blood pressure readings on millions of people over the years, it became clear that hypertension is a major threat to health, increasing the risk of stroke, heart attack, congestive heart failure, kidney failure, and visual loss. And as data accumulated, it also became clear that there is no bright line between a healthy blood pressure and a harmful one; in general, the lower the pressure, the better.

Cutting back on our most common seasoning is a necessity for some people, but not for everyone.

"The history of the Americas is one of constant warfare over salt."

A cell phone or smartphone can do so much more than make calls, send text messages, and play games.

Hundreds of heart-related applications are available for the iPhone, Android, Blackberry, and other smartphones. Many are little more than glorified diaries or pamphlets. A growing number, though, are tapping into the sophisticated technology packed into these phones.

At least half of the 80 million Americans with high blood pressure don't have it under control. Sometimes poor control stems from lack of trying. A growing number of people, though, have what's called resistant hypertension — blood pressure that stays stubbornly above the target (see "Blood pressure goals") in spite of lifestyle changes and medications.

Persistently high blood pressure is a problem. It is a key contributor to stroke, heart failure, and other cardiovascular conditions.

When it comes to fighting high blood pressure, the average American diet delivers too much sodium and too little potassium. Eating to reverse this imbalance could prevent or control high blood pressure and translate into fewer heart attacks, strokes, and deaths from heart disease.

Normal body levels of potassium are important for muscle function. Potassium relaxes the walls of the blood vessels, lowering blood pressure and protecting against muscle cramping. A number of studies have shown an association between low potassium intake and increased blood pressure and higher risk of stroke. On the flip side, people who already have high blood pressure can significantly lower their systolic (top number) blood pressure by increasing their potassium intake when they choose to eat healthy foods.

Thiazide diuretics like hydrochlorothiazide (Esidrix, HydroDIURIL, other brands) continue to be a very effective way to lower blood pressure for people with hypertension. They're inexpensive, and results from large studies have shown them to be at least as effective as other types of blood pressure drugs for most patients.

But if you're taking a diuretic, your potassium levels need to be watched. These drugs direct the kidneys to pump water and sodium into the urine. Unfortunately, potassium also slips through the open floodgates. A low potassium level can cause muscle weakness, cramping, or an abnormal heartbeat, which is especially dangerous for people with heart problems.

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.

Image: -goldy-/Thinkstock

News Briefs

A popular smartphone app that estimates your blood pressure doesn't provide reliable readings. In fact, more than three-quarters of people with high blood pressure who use the Instant Blood Pressure app will be falsely reassured that their blood pressure is normal, according to a small study that compared the app results to readings taken with a traditional blood pressure cuff.

To use the app, you put the top edge of your phone on the left side of your chest while holding your right index finger over the smartphone's camera. The app—which was among the top 50 best-selling iPhone apps for about five months—is no longer for sale, for unclear reasons. But it's still installed on a vast number of iPhones, and similar apps are still available, according to a research letter published online March 2 by JAMA Internal Medicine. Bottom line: Don't use any app that uses the phone itself to measure your blood pressure.

Chronic stress can have a silent, yet dangerous, impact on your cardiovascular health. Here is how to lessen its effect.

Dialing down your stress can protect your heart from high blood pressure and inflammation.
Image: Donskarpo/Thinkstock

Stress is not always a bad thing. In fact, it has an important job. Stress motivates you to be alert, energetic, and focused, especially in times of trouble. But too much of anything can lead to problems.