Blood Pressure Archive

Ask the doctors

Q. The July 2017 issue of Harvard Women's Health Watch spoke about the potential problems related to low blood pressure when taking blood pressure medication. My readings meet the definition of low blood pressure outlined in the article, but I don't take any medication. Should I be concerned, and if so, what should I do to raise my blood pressure?

A. In general, blood pressure is deemed too low only if it causes symptoms. A normal blood pressure is defined as a reading below 120/80 millimeters of mercury (mm Hg), and some experts consider your blood pressure low only if it dips below 90/60 mm Hg. However, a low reading can be normal for some people. Your doctor probably won't be too concerned about it unless it occurs suddenly; you have an underlying health condition that could cause low blood pressure, such as heart failure; or you are experiencing symptoms such as dizziness, lightheadedness, fainting, fatigue, or nausea. Some medications, such as diuretics (water pills), some antidepressants, and beta blockers, among others, can also cause low blood pressure. But since you aren't taking any medication, this is not an issue. If you are having symptoms related to your low blood pressure, this is something you definitely want to mention to your doctor. But if you've always had low blood pressure and you're not experiencing any problems, it's likely that this is normal for your body.

Research we're watching

Last month, Harvard Women's Health Watch talked about how high blood pressure can cause a series of tiny strokes that damage your brain, increasing your risk of dementia and cognitive changes. A study in the August 8 issue of Circulation shows that this might not be the only concern when it comes to blood pressure and your mind. Researchers in Japan found that large and frequent fluctuations in blood pressure — not just high blood pressure — was associated with an increased risk of both Alzheimer's disease and vascular dementia.

The study authors asked 1,674 dementia-free participants ages 60 and older to measure their blood pressure at home, three times every morning, for about four weeks. They followed up about five years later to see who went on to develop dementia.

Want to keep your mind sharp? Be aggressive about treating your high blood pressure.

 Image: © adrian825/Thinkstock

If you're like a lot of people, you probably think of your heart when you think about blood pressure. But you should also think about your mind.

"High blood pressure is not just a disease or condition. It's actually a risk factor. It's a risk factor for heart disease and stroke, and it's a risk factor for cognitive decline and dementia," says Dr. Natalia Rost, a stroke neurologist at Massachusetts General Hospital and associate professor of neurology at Harvard Medical School.

Research we're watching

To provide more information on the value of statins for older people, which is still a matter of debate, researchers analyzed data on people over 65 who were enrolled in ALLHAT-LLT, a large study conducted between 1994 and 2002.

All participants (average age 71) had high cholesterol and high blood pressure but not heart disease. They were randomly assigned to two groups. One group, of 704 women and 763 men, took pravastatin (Pravachol). The other group, of 711 women and 689 men, didn't take a statin. The analysis indicated that during the five-year study period, there was no significant difference between the groups in the frequency of heart attacks, deaths from heart disease, or deaths from any cause, either among participants ages 65 to 74 or among those 75 or older. The results were published online May 22, 2017, by JAMA Internal Medicine.

New guidelines suggest that people with no history of cardiovascular disease may not benefit from more aggressive treatment.

High blood pressure remains a strong indicator for heart attack or stroke risk. But how high is too high?

The American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP) recently released updated guidelines for treating hypertension (high blood pressure) in adults ages 60 and older.

Learn why fainting occurs and when you should seek medical attention.

One minute you're feeling a bit woozy; the next thing you know, you're flat on your back wondering what happened. No matter what you call it — swooning, passing out, or fainting — the experience is surprisingly common. About a third of people say they've fainted at least once.

Defined as a sudden, temporary loss of consciousness, fainting occurs when something interrupts blood flow to the brain. Doctors call it syncope, which comes from a Greek word meaning "contraction" or "cut off." Although often harmless, fainting can cause injuries and sometimes signals a problem with the heart or circulatory system.

In the journals

A study of almost 7,500 men and women ages 65 or older suggests that among those with weak grip strength, elevated blood pressure does not serve as a sign of a high risk of early death.

Grip strength is a commonly used measure to assess frailty in older individuals. The research, published online March 17, 2017, by the Journal of the American Geriatrics Society, measured the participants' grip strength and blood pressure. Grip strength was measured with a hand dynamometer, with "weak" defined as a reading of less than 26 kilograms (kg) for men.

Recent findings raise concerns about lowering diastolic blood pressure — the second number in your blood pressure reading — too far.

 Image: © Wavebreakmedia/Thinkstock

More of us than ever before are taking medications to lower our blood pressure. Longstanding guidelines suggest that most people should aim for a systolic blood pressure (the first number in a reading) no higher than 140 millimeters of mercury (mm Hg). But in 2015, the results of the Systolic Blood Pressure Intervention Trial (SPRINT) suggested that reaching a target of 120 mm Hg could further reduce the risks associated with high blood pressure, including heart attack, stroke, heart failure, and death.

Yet reaching that lower target often requires three blood pressure medications, which can increase the likelihood of side effects. Two observational studies and one clinical trial have raised concerns about lowering blood pressure — particularly diastolic pressure — too far. Diastolic blood pressure (the second number in a reading) represents the pressure between beats when the heart relaxes. "When your systolic blood pressure gets too low, it can manifest as lightheadedness, fainting, and weakness. But low diastolic pressure by itself doesn't have any symptoms," says Dr. Paul Conlin, professor of medicine at Harvard Medical School and chief of medicine at the VA Boston Healthcare System.

If so, be extra vigilant about measuring and managing your blood pressure and cholesterol.

Filling out those family history forms at the doctor's office can be tedious. But sometimes, the devil is in those details. Because heart disease is so common, many people check "yes" to the question about whether their father or mother had heart disease. But if your father had a heart attack at age 77, that's likely different than if his heart attack happened when he was only 44.

"If you have any family history of heart disease, that should serve as a keen reminder to pay attention to factors that can raise your risk of a heart attack, such as high cholesterol, high blood pressure, and diabetes," says Dr. Howard Sesso, an epidemiologist with the division of preventive medicine at Harvard-affiliated Brigham and Women's Hospital. But if a parent or sibling had a premature heart attack, that's an even stronger signal to be more proactive in monitoring and lowering your risk, he adds. A premature or early heart attack is one that occurs before age 55 in a man or before age 65 in a woman.

Research we're watching

The more physically active you are, the lower your risk of high blood pressure, a study in the April 2017 issue of Hypertension suggests.

Researchers pooled data from 29 studies involving a total of more than 330,000 people, about 20% of whom had high blood pressure. They examined the association between high blood pressure and leisure-time physical activity (walking, dancing, or gardening, for example) as measured by metabolic equivalents (METs).