Blood Pressure Archive

In the journals

Blood pressure readings are usually done on only one arm, but a new analysis makes the case for checking both arms, as the difference between them may suggest an elevated risk for heart disease. The findings were published in the February 2021 issue of Hypertension.

Researchers examined 24 studies that measured blood pressure in both arms in 53,827 adults without high blood pressure. They found that a difference of more than five points between the left and right arm systolic readings (the top number) was linked with a 9% higher risk for a first-time heart attack or stroke and a 6% increase in cardiovascular death within 10 years. The greater the difference between the two readings, the higher the risk.

Ask the doctor

Q. My doctor told me I should get a home monitor to keep tabs on my blood pressure. Which number is most important in the reading, the top or the bottom one?

A. This question comes up often, perhaps because doctors and patients alike tend to pay more attention to the top (first) number, known as systolic pressure. It reflects the amount of pressure inside the arteries as the heart contracts. The bottom (second) number, diastolic pressure, is always lower since it reflects the pressure inside the arteries during the resting phase between heartbeats.

Known as orthostatic hypotension, this condition can leave people dizzy and lightheaded. For some, it may also be a harbinger of heart disease.

Have you ever felt a bit woozy just after standing up? When you transition from sitting to standing, gravity causes blood to pool in your legs. Sometimes — especially if you're dehydrated or overheated — it takes your body a moment to push blood upward, causing a brief delay in blood flow to the brain.

For most people, this phenomenon occurs just once in a while and usually isn't a serious problem. But age, some medications, and certain medical conditions can interfere with the body's normal mechanism for regulating blood pressure (see "Responding to pressure: The role of baroreceptors"). If that happens, your blood pressure may drop dramatically when you stand up. Known as orthostatic hypotension (OH), the problem affects about 5% of people younger than 50. But up to 20% of people ages 70 and older may have OH.

News briefs

Here's more incentive to keep your blood pressure under control: a large study published online Dec. 14, 2020, by the journal Hypertension suggests that high blood pressure hastens decline in cognitive abilities (thinking skills). Researchers analyzed two health assessments, taken about four years apart, of more than 7,000 middle-aged and older people in Brazil. The assessments noted changes in a number of cognitive skills, such as memory, language, and concentration. Regardless of age, people with high blood pressure had faster declines in cognitive performance, compared with people who had normal blood pressure. The researchers classified blood pressure as high if the top number was 130 or higher and the bottom number was 80 or higher. But even people with a top number between 120 and 130 experienced faster cognitive decline than people with normal blood pressure. The silver lining: the researchers found that treating high blood pressure at any age appeared to reduce or prevent accelerated cognitive decline. High blood pressure can be controlled with medications as well as pill-free approaches, such as losing weight, exercising, eating a heart-healthy diet, reducing alcohol intake, managing stress, and quitting smoking.

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Cardiovascular problems can conspire to put a damper on sexual enjoyment. Talking to your doctor and your partner can help.

A physical connection with your romantic partner is often an important part of a fulfilling relationship. But when it comes to matters of the heart, the health of your heart matters.

"A satisfying sex life depends on physical health, psychological well-being, and the quality of the relationship," says Dr. Jan Shifren, who directs the Massachusetts General Hospital Midlife Women's Health Center. Heart disease and related conditions can influence all three of those factors in both men and women. Here's a look at the range of those effects and some possible solutions.

In the journals

Do you know if you have hypertension (high blood pressure)? And if you do, are you treating it effectively? Study findings published online Sept. 9, 2020, by JAMA found that people's awareness and control of their high blood pressure have both dropped in recent years, especially among older adults.

The study pulled data from the National Health and Nutrition Examination Survey. It found that the number of people who knew they had hypertension fell 8% from 2013 to 2018. Among those who were aware of their condition, more than half did not manage it adequately. In particular, adults ages 60 and older were less likely to control their high blood pressure than younger people. Lack of engagement could be a factor. Researchers noted that among people who hadn't been to their doctor in the past year, fewer than 10% had controlled their blood pressure.

Research we're watching

Widely considered the healthiest diet for your heart, the Mediterranean diet is rich in plant-based foods and features only small amounts of meat and dairy products. But a variation that includes more green plant foods may be even better for you, a small study suggests.

The study included 294 sedentary, moderately obese people whom researchers randomly divided into three groups. Each received different dietary advice: a standard healthy diet, a low-calorie Mediterranean diet, or a "green" Mediterranean diet. Both Mediterranean diet groups included about a quarter-cup of walnuts daily, and poultry and fish replaced beef and lamb.

Research we're watching

Reliable blood pressure readings are vital for diagnosing high blood pressure and estimating a person's risk of heart disease. New research suggests that using a home blood pressure monitor may be more dependable than other methods.

Doctors have long relied on office visits to check people's blood pressure. But growing evidence shows that readings done outside a doctor's office are more closely linked to a person's risk of heart-related problems. Ambulatory blood pressure monitoring (ABPM) involves wearing a device that automatically records blood pressure every 30 to 60 minutes for 24 hours, but it's not widely available.

Ask the doctor

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Q. I have high blood pressure and have been checking my blood pressure more often since my doctor added another drug. But lately, my readings have been all over the place. For example, one morning it was 127/70, but then it was 170/100 in the late afternoon. What's going on?

A. You may have a condition known as labile hypertension, which refers to blood pressure that fluctuates far more than usual. Everyone's blood pressure rises and falls many times during the course of a single day, sometimes even within minutes. Many factors contribute to these changes, including physical activity, emotion, body position, diet (especially salt and alcohol intake), and sleep deprivation. However, there is no clear definition or standard criteria to distinguish between normal and abnormal fluctuations.

Q. When doctors interpret a blood pressure reading, should they also consider the heart rate? I am a 78-year-old man and have had high blood pressure (under control) for more than 40 years. I frequently monitor my blood pressure at home, resting for five minutes before I take the reading. My blood pressure is often higher when my heart rate is close to its usual resting rate (about 50 beats per minute) and lower when my heart is beating faster than that. Can the body's demands that cause higher blood pressure be partially satisfied by a faster heart rate?

A. First, let me congratulate you on monitoring your blood pressure at home. This is a great way for you to take control of your high blood pressure, and a good step toward preventing a stroke. Knowing that your blood pressure at home is under consistent control is more important than getting isolated readings at the doctor's office. You are also resting before taking the reading, and this is important to avoid spuriously high readings that happen when someone rushes around, and then sits down quickly to take a blood pressure reading. (Readers interested in monitoring their blood pressure at home can watch a video of how this is done at www.health.harvard.edu/128.)