The definition of high blood pressure has reached a new low—130 is the new 140. According to guidelines set by the American Heart Association and the American College of Cardiology in late 2017, if your systolic (upper) number is 130 mm Hg or higher…and/or your diastolic (lower) number is 80 mm Hg or higher…you have high blood pressure, aka hypertension. The previous threshold was 140 mm Hg. (Diastolic, the lower number, is less important at predicting cardiovascular risk.)

Overnight, more than 30 million Americans “got” high blood pressure. Combined with those who met the earlier threshold, that’s a total of about 103 million people. As an advocate for using less medicine whenever possible, I’m worried by these new guidelines. That’s why I wrote an article in The New York Times titled, “Don’t Let New Blood Pressure Guidelines Raise Yours.” And it’s why I enthusiastically agreed to work with Bottom Line Personal on this article. It’s not that controlling very high blood pressure isn’t important. It’s critical. Treating very high blood pressure with medication is one of the most important preventive interventions doctors do.

But doctors also can do too much prescribing. Aggressive medical management to reach the new goals for people at the margin may have only modest benefits that don’t outweigh the risks for side effects. In a blow to wide acceptance, the American Academy of Family Physicians (AAFP) declined to endorse the new guidelines because they don’t meet that organization’s standards for medical evidence. It’s sticking with the previous guidelines.

When doctors disagree, it can be confusing for patients. Here are some facts to help you and your physician make the right decision…

MODEST NEW BENEFITS

While the new guidelines emphasize lifestyle changes such as getting more exercise, losing weight if you need to and eating a healthful diet as the first line of defense—good advice for all of us—the likely practical effect will be to push many more people into drug treatment. So let’s examine the benefits.

The new guidelines stem from a federally funded study called the Systolic Blood Pressure Intervention Trial (SPRINT). It covered people over age 50 at high risk for cardiovascular disease. Half were treated to bring their systolic blood pressure down to less than 140 and half to bring it down to less than 120.

Result: Compared with those treated to less than 140, those treated to less than 120 had 25% lower risk for heart attack, stroke, heart failure and death from cardiovascular causes. Sounds impressive, right? But in reality, over the course of the three-year study, about 6% of participants who aimed for 120 had cardiovascular “events” such as heart attacks—compared with 8% of those who aimed for 140. That’s only a two-percentage-point difference.

The truth is, while reducing very high blood pressure—say, from 160 or 180 to 140—has enormous benefits, going from 140 to 130 doesn’t. According to a review that included 74 trials and more than 300,000 patients that was published in JAMA Internal Medicine, bringing blood pressure levels below 140 did not help prevent a first heart attack or stroke, reduce the rate of cardiovascular disease or help prevent death overall.

RISKS OF AGGRESSIVE TREATMENT

In the SPRINT trial, getting to a blood pressure goal of less than 120 required an average of three different drugs per patient—compared with two drugs for a 140 goal. While that extra drug didn’t substantially increase side effects in that trial, it’s still true that 38% of patients in the 120-target group had adverse events, including abnormally low blood pressure, loss of consciousness and acute kidney injury. I’m concerned about adding even one extra prescription medication, especially for many elderly patients who already may take eight or even 10 medications a day.

Blood pressure drugs, like all drugs, have side effects. The type called beta-blockers can cause dizziness, weakness and fatigue, as can ACE inhibitors, ­angiotensin II receptor blockers and alpha blockers. Dizziness and light-headedness can result in more falls, which is particularly dangerous for older people, making them more prone to fractures—including hip fractures, which can have devastating consequences for health and independence.

These concerns are among the reasons that the AAFP and the American College of Physicians came out with blood pressure treatment guidelines specifically for people age 60 and older in 2017.

Recommendations: Doctors should prescribe drugs for healthy patients only when systolic levels are 150 or higher. For patients at high cardiovascular risk, especially stroke patients, doctors are advised to start treatment at 140.

OVERDIAGNOSIS RISK

There’s a bigger problem in extrapolating the results of the SPRINT trial to the real world. Blood pressure is an extremely volatile variable, and it can change within minutes in reaction to stress, activity or just the anxiety of sitting in a doctor’s waiting room. (For how to get a good blood pressure reading, see below.) To remove those stressors, the SPRINT researchers had patients measure their own blood pressure (using an automated cuff) after five minutes of quiet rest without staff in the room.

This may be an ideal way to measure blood pressure, but it’s not what happens in the real world. You might have had a blood pressure reading of 130 in a situation such as the SPRINT trial, while it might be 140 or even higher when measured in your doctor’s office. In practice, that may lead to many people being overmedicated.

WHAT TO DO NOW

Have the new guidelines pushed you into the official “high blood pressure” range? I hope you now realize that it’s not a medical emergency if they have. But it’s an opportunity to talk to your doctor about what blood pressure goal is right for you, given your age and risk factors.

Even if you wind up needing medication, a lifestyle plan is enormously important. Limit alcoholic drinks to no more than one a day if you’re a woman or two a day if you’re a man. Revamp your diet to include plenty of fruits and vegetables and whole grains. Reduce your salt intake. Exercise regularly. If you smoke, quit. Lose weight if you need to. Find healthy ways to manage stress.

Ironically, the recent dramatic increase in the number of people with “high” blood pressure can distract patients and doctors from focusing on these important lifestyle changes. Doing those things is good for blood sugar, for better sleep and for overall well-being, regardless of blood pressure.

THE RIGHT WAY TO MEASURE YOUR BLOOD PRESSURE AT HOME

If you’re concerned about your blood pressure, and especially if you’ve started to take medication to bring it down, consider measuring your blood pressure yourself at home. Many physicians recommend this ­do-it-yourself approach because it can help you become more aware of the things that move your blood pressure up or down.

Buy a monitor with an inflatable upper-arm cuff—more reliable than those with wrist cuffs or fingertip monitors. Follow these tips when you measure your pressure…

Relax. Don’t exercise or drink ­caffeinated drinks or alcohol for at least 30 minutes before measuring. Make sure your bladder is empty…sit quietly for five minutes before you take a measurement…sit still while you measure.

Watch your posture. Sit with your back against a straight-back chair…feet flat on the floor, legs uncrossed. Support your arm on a flat surface with your upper arm at heart level. The middle of the blood pressure cuff should be placed just above where the elbow bends.

Place the cuff directly on your bare arm, not over clothing.

Take your pressure at the same time every day. Either morning or evening is fine. It doesn’t matter whether you do it before or after taking medication—just be consistent.

Take two or three readings one minute apart. Print out or write down the results or store them in your device’s built-in memory.

Ask your doctor’s office if you can do a practice run there. That way you can be sure that you are using the monitor correctly at home.

Caution: Don’t rely solely on your at-home readings. Compare them with the readings you get in your doctor’s office as a backup.