What You Need to Know About Your Blood Pressure
Getting it checked, changing your lifestyle, taking medication can keep it under control
En español | More than 100 million U.S. adults — almost half — have high blood pressure, according to new statistics from the American Heart Association (AHA). Even scarier, the number of deaths from hypertension rose by nearly 38 percent from 2005 to 2015. “Many people with high blood pressure aren't aware that they have it, and even in those cases that they are aware, their condition isn't well controlled,” says Willie Lawrence, chief of cardiology at the Research Medical Center in Kansas City, Missouri, and a spokesperson for the AHA. However high your own numbers, experts say there are critical things to know about this silent killer.
More people are being diagnosed with hypertension
The sky-high numbers of Americans with high blood pressure is due in part to the fact that standards changed in 2017. And when the American Heart Association and the American College of Cardiology (ACC) redefined blood pressure limits, the new, more stringent standards pushed over 31 million Americans from borderline high blood pressure to bona fide hypertension.
"You're now considered to have hypertension if you have blood pressure of at least 130 for the systolic [top] number or 80 for the diastolic [bottom] number,” Lawrence explains. (Previously, the number was 140/90.)
Experts note there is a solid scientific basis and a real need for the lower thresholds: If all American adults over age 45 were able to keep their blood pressure below the new standard of 130/80, it would prevent 3 million strokes and heart attacks over the next decade, according to a 2018 study published in the medical journal Circulation.
'White coat hypertension’ can be dangerous
Sometimes, people who have high blood pressure at their doctor's office actually have normal blood pressure in other settings, such as their home, a condition known as “white coat hypertension.” But although many doctors dismiss it, new research suggests the in-office spike may portend trouble ahead: Untreated white coat hypertension appears to more than double the risk of dying from heart disease, according to a review published in June in Annals of Internal Medicine.
"It may be that patients with white coat hypertension experience a rise in blood pressure whenever they're stressed,” explains Lawrence. If your blood pressure is frequently high in your doctor's office but normal at home, you may want to consider 24-hour ambulatory blood pressure monitoring, where your physician sends you home with a device that checks your blood pressure every 20 to 30 minutes during the day and hourly at night. This will help your doctor determine whether your blood pressure rises with anything even remotely stressful, or if it's just an in-office occurrence.
Even if your blood pressure seems perfectly normal at your doctor's office, it's a good idea to periodically get your blood pressure checked, either with a home blood pressure monitor or at a walk-in clinic at a pharmacy. “There's a condition known as ‘masked hypertension,’ where your blood pressure is normal at your doctor's office but it goes up at other times of day or in other settings, such as work or at home,” Lawrence says. Up to 1 in 8 adult Americans may have this condition, according to a 2017 study published in the American Journal of Epidemiology. If you get an elevated result more than once or twice, talk to your doctor.
Lifestyle makes a huge difference
If you're diagnosed with stage 1 hypertension (a top number between 130 and 139, and/or a bottom number between 80 and 89), you may think you need to start medication. But for most people in this group, the only prescription is for a change in lifestyle, says Michael Hochman, director of the Gehr Family Center for Health Systems Science at Keck Medicine of USC in Los Angeles. In fact, a 2017 Johns Hopkins study published in the Journal of the American College of Cardiology of more than 400 adults with stage 1 high blood pressure found that combining a low-salt diet with the heart-healthy DASH (dietary approaches to stop hypertension) diet rich in fruits, vegetables and whole grains, plus low-fat dairy, fish, poultry, beans, seeds and nuts, lowered blood pressure as much as medication. Similarly, a study presented last year at the American Heart Association's annual meeting found that people with hypertension who exercised three times a week and followed the DASH diet were able to lower their blood pressure on average 16 mm Hg systolic and 10 mm Hg diastolic without medication after 16 weeks.
You also don't need to do much exercise to see results: Just 30 minutes of moderate morning exercise like walking on a treadmill lowers blood pressure for the rest of the day among older men and women who are overweight or obese, according to a study published in February in the medical journal Hypertension. The study also found that women who take brief, frequent breaks from sitting throughout the day enhanced the blood pressure benefits of morning exercise even more.
It's also important to limit salt and alcohol, both of which can raise blood pressure, says William Haley, a cardiologist at the Mayo Clinic in Jacksonville, Florida. The AHA recommends people with high blood pressure keep their sodium intake below 1,500 mg a day. (Check labels, since up to 75 percent of the sodium people consume is hidden in processed foods.) Limit yourself to one drink a day (the equivalent of four ounces of wine) if you're a woman, and two drinks if you're a man.
If you do need medications, you may need more than one
"About 40 percent of my patients need three blood pressure medications to get their hypertension under control,” says Haley. If your systolic blood pressure is between 140 and 145, the first line of treatment is usually a diuretic like chlorthalidone or hydrochlorothiazide. But these can drive up blood sugar levels, Haley says, so if you have type 2 diabetes or are at risk of it, he recommends starting instead with either an ACE inhibitor or a calcium channel blocker. If you have kidney disease, ACE inhibitors or another type of blood pressure medication, angiotensin II receptor blockers (ARBs), are recommended. These have both been shown to slow the progression of kidney disease.
If your systolic blood pressure is higher than 145, you'll usually need to start with two of these drugs, and, if your blood pressure isn't brought below 130 after a month or two, three drugs will likely be considered. The preferred three-drug regimen is either an ACE inhibitor or ARB, a long-acting calcium channel blocker such as amlodipine, and a long-acting thiazide-like diuretic like chlorthalidone, says Thomas Brott, professor of neurology and director for research at the Mayo Clinic in Jacksonville. The good news is that a multidrug approach seems to be very effective while minimizing side effects like weakness, dizziness, headache and muscle cramps. A 2017 review published in the medical journal Hypertension of over 20,000 people with high blood pressure found that combining two medications, each at a quarter dose, was just as effective as taking one blood pressure medication at the standard dose — and taking four medications each at a quarter dose worked twice as well.
Controlling blood pressure helps more than your heart
Treating hypertension may also lower your chances of developing mild cognitive impairment (MCI), a condition that's often a precursor to dementia. People who tried to get their blood pressure under 120/80 were 19 percent less likely to develop MCI than those who aimed for simply under 140/90, according to a study published this year in the Journal of the American Medical Association. “What's good for your heart as far as blood pressure control is good for your brain, too,” says Luke Laffin, a cardiologist at the Cleveland Clinic.
But high blood pressure affects more than your brain and your heart: It affects your kidneys, too. Uncontrolled high blood pressure damages the arteries around the organs, making it harder to deliver enough blood to your kidney tissue, explains Laffin. This means your kidneys aren't able to get the oxygen and nutrients they need, which makes it much harder for them to do their job of filtering blood and regulating fluid in your body. It also makes it more difficult for them to produce the hormone aldosterone, which helps your body regulate blood pressure. As a result, your body gets trapped in a vicious cycle where both your blood pressure and kidney function continue to worsen.
High blood pressure also has other insidious effects, like increasing risk of impotence in men and lessening sexual arousal in women. It can also damage the tiny blood vessels around your eyes, causing blurred or even complete loss of vision. That's why it's so important to keep track of your blood pressure numbers and, if they're elevated, take steps to lower them, says Laffin.