When Raymond R. Townsend, M.D., was in medical school in the 1970s, the formula for blood pressure was simple. "Doctors were taught that the normal top blood pressure number was 100 plus a person's age," says Townsend, a professor of medicine at the University of Pennsylvania. "We now know that numbers even close to that high — as you get older — are very dangerous." Research has come a long way, but there's still controversy about optimal levels, the best treatments and even how to measure blood pressure. There's no debate, however, that high blood pressure can lead to heart attacks, stroke, vision problems, even dementia. Here are 15 must-know facts about high blood pressure that just might save your life.
1. Hypertension isn't inevitable — but blood pressure climbs as you age
At age 75, Suzanne Oparil, M.D., still has great blood pressure. "It's mostly the luck of genes," says Oparil, a professor of medicine at the University of Alabama at Birmingham, whose research has played a key role in hypertension guidelines. Like Oparil, some of us may never develop high blood pressure. But most people see an increase in the upper number, systolic blood pressure, starting around age 40. About 7 percent of Americans ages 18 to 39 have hypertension, defined as blood pressure that is 140/90 or higher. That incidence climbs to 32 percent among those ages 40 to 59, and 65 percent for Americans 60-plus. Part of the reason: Arteries tend to stiffen with age.
2. Even dangerously high blood pressure often has no symptoms
Your blood pressure can be through the roof, and the only way you might know it is by getting it checked. Getting a reliable reading, though, can be tricky. Blood pressure numbers can vary 30 to 40 points through the day, Oparil says, typically falling at night and surging in the morning. "It can even spike just because you're having your blood pressure measured, a phenomenon called 'white coat hypertension.' " The gold standard for recording blood pressure is a 24-hour test that measures pressure three or four times an hour during the day and every 30 minutes at night. Since insurance typically doesn't cover the test, many doctors suggest buying your own automated upper-arm blood pressure monitor.
3. The top number is the one to watch when you're over 50
The top number, systolic pressure, measures the force at the moment the heart beats, pumping blood throughout the body. The bottom number (diastolic pressure) measures pressure between beats, when blood flows back to the heart. "The top number is the one that matters, because systolic blood pressure is the peak force that your arteries and your vital organs experience with each heartbeat," says Sheila Sahni, M.D., a cardiovascular disease expert at UCLA Medical Center. "When pressure increases, it can damage your kidneys, your eyes, your brain, even the lining of blood vessels." The lower number, diastolic blood pressure, typically peaks at about age 55 and then gradually falls.
4. Experts don't agree on what the ideal systolic blood pressure should be
Researchers are still debating the ideal blood-pressure target for people over 50. Until recently, the best evidence suggested that a reasonable target was systolic blood pressure below 140 millimeters of mercury, or less than 150 for people over 60. A September 2015 report from the Systolic Blood Pressure Intervention Trial, or SPRINT, toppled that advice. In the randomized trial of more than 9,300 people at high risk of heart disease or who already had kidney disease, nearly 30 percent of whom were age 75 or older, researchers compared one group of volunteers with systolic blood pressure of 140 to another group that aggressively lowered theirs to 120. People in the 120 group were one-third less likely to suffer heart failure, a nonfatal heart attack or a stroke during the five-year trial.
5. The optimum blood pressure target is different for different people
Official guidelines are just that: They guide doctors and patients. "But every patient is different," says Townsend, one of the country's leading experts on hypertension. For patients at low cardiovascular risk, a higher systolic target may be acceptable. The same may be true for some high-risk patients who can't tolerate aggressive therapy because of side effects. "With a 69-year-old who's already taking four blood pressure medications to get down to 135, you have to think carefully about whether it's worth adding another medication," Townsend says. The best advice is to ask your doctor what's right for you.
6. Healthy lifestyle changes can work as well as a pill
Cutting back on salt and eating plenty of fruits and vegetables can drop high blood pressure by about 5 points. Losing weight also helps. Dropping 11 pounds can shave off more than 4 points from your systolic blood pressure, studies show. In a 2016 review, Swedish researchers found that physical activity can reduce systolic pressure by an average of 11 points in people with hypertension. "If you have moderately elevated blood pressure, healthy changes might mean you won't need medication," says Glenn M. Chertow, M.D., professor of medicine at Stanford University in Palo Alto, Calif.
7. Coffee makes blood pressure spike — but don't fret
Researchers have long known that a cup of high-octane coffee makes blood pressure jump. In a 2011 article in the American Journal of Clinical Nutrition, researchers concluded that 200 to 300 milligrams of caffeine (or two or three 8-ounce coffees) increased systolic blood pressure by an average of 8 points. The spike lasts about three hours, but there appears to be no long-term effect.
8. Breathe deep to bring your number down
Simply slowing your breathing down to six breaths in 30 seconds has been shown to bring systolic blood pressure down by about 3 points — at least temporarily. An FDA-approved portable computerized device, called RESPeRATE, uses tones to guide you through sessions of deep breathing.
9. Keeping an eye on salt becomes more important as you get older
Salty foods can raise blood pressure, but recommendations to reduce salt have long been controversial. One reason: Not everyone is salt sensitive. But as people age, they may tend to pile on more salt, because their sense of taste fades. Federal guidelines recommend less than 1,500 mg of sodium a day for people over 50 — far less than the 3,400 mg Americans typically consume. Most salt is hidden in processed foods, so check labels and choose low-sodium items. When adding salt, keep in mind that one-quarter of a teaspoon contains 575 mg of sodium.
10. Simple hand-grip exercises can help
In a landmark 2013 Hypertension report on alternative ways to lower blood pressure, researchers confirmed that hand-grip exercises can reduce your number by about 10 percent. Inexpensive hand grippers available online or at a local sporting goods store ($10 to $15) are effective. Squeeze the gripper for 2 minutes at a time, for a total of 12 to 15 minutes, three times a week.
11. New medicines aren't necessarily better than the older ones
Doctors typically begin treating high blood pressure with diuretics, or "water pills," some of the oldest hypertension medications around. They work by removing excess sodium and water from the body. Newer medications called ACE (angiotensin-converting enzyme) inhibitors prevent the body from producing a hormone that raises blood pressure. Angiotensin II receptor blockers, or ARBs, block the action of the same hormone. Research shows that the newer meds may be no more effective than diuretics, though they often have fewer side effects.
12. For many people, one blood pressure medication isn't enough
If your blood pressure is moderately elevated, you may need only one pill to bring it down, but many people end up having to take several. "Individual blood pressure medications typically lower blood pressure by only a few points," Chertow says. "And when you increase the dose, there's a point of diminishing returns. So, depending on the patient, we combine different classes of medications for optimal effect."
13. Over-the-counter medicines may be raising your blood pressure
"Many cold medications contain pseudoephedrine, which clamps down on blood vessels, raising blood pressure," Sahni says. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as Aleve, Advil and Motrin, can also raise blood pressure by 3 to 6 points. That's enough to contribute to cardiovascular risk if you take them on a regular basis.
14. Blood pressure can dip too low
The danger is greatest when people stand up and blood pressure isn't strong enough to pump blood to the brain — a phenomenon called orthostatic hypotension. Older people are particularly at risk of falls that may cause fractures. If you're on medication and experience dizziness, talk to your doctor. A change in your prescription may help.
15. Sticking with treatment is crucial
A combination of lifestyle changes and medication is usually enough to bring your numbers down out of the danger zone. But once you hit the target, it's essential to go on taking your pills and following healthier habits. "Too many people get lazy about taking blood pressure medications. Or they stop taking them if they think they're having side effects," Sahni says. If you go off your medications, your blood pressure will go back up. Since systolic blood pressure typically rises with age, it's also important to monitor your blood pressure regularly. Most people with high blood pressure need to adjust their medications periodically.
This story originally appeared in the June 2016 AARP Bulletin.