The percentage of Americans with high blood pressure jumped from 32 percent to 46 percent today, when the American Heart Association and the American College of Cardiology issued new guidelines for the condition.

But that doesn't mean that all those people suddenly need to be on blood pressure medication, our experts say.

On Monday, the AHA and ACC redefined high blood pressure as a reading of at least 130 millimeters of mercury for the systolic (top) number or 80 for the diastolic (bottom) number. Previously, the cutoffs had been a top number of 140 and a lower number of 90.

The new definition will especially affect younger people, tripling the number or men under age 45 considered to have hypertension and doubling the number of women under age 45 with that condition.

The new definition also eliminates the category of “pre-hypertension," which had been considered an upper reading in the 130s and a lower reading in the 80s.

“We now know that a blood pressure level between 130-139/80-89 doubles your risk of cardiovascular complications such as a heart attack compared to people whose blood pressure is under 120/80,” says Paul Whelton, M.D., lead author of the guidelines and the Show Chwan professor of global public health at the Tulane University School of Public Health in New Orleans. That’s because damage to blood vessels begins as soon as blood pressure is elevated.

For most people who find themselves in that range, however, changes in diet and exercise routine—not drugs—are what's needed to bring those numbers back down to normal.

Understanding the New Guidelines

The new guidelines put blood pressure readings in five different categories:

• Normal. A top number less than 120 and a bottom number less than 80.
• Elevated.
A top number between 120 and 129, and a bottom number less than 80.
• Stage 1.
 A top number between 130 and 139, or a bottom number between 80 and 89.
• Stage 2.
A top number of 140 or higher, or a bottom number of 90 or higher.
• Hypertensive crisis.
A top number over 180 or a bottom number over 120. 

Our experts say the reclassification of high blood pressure is a good thing.

“Flagging elevated blood pressure earlier will hopefully motivate people to make lifestyle changes—such as eating a heart-healthy diet and exercising—that can dramatically lower blood pressure in the long term,” says Consumer Reports' chief medical adviser Marvin M. Lipman, M.D.

But while it’s important to regularly monitor your blood pressure and work on lifestyle changes if you’re above the 120/80 range, "it’s also crucial not to rush to medication," Lipman says.

Drug treatment to lower blood pressure is only associated with a reduced risk of death and cardiovascular disease in people whose baseline systolic blood pressure is 140 or higher, according to a review of the research published Monday in the medical journal JAMA; there’s no strong evidence that such pills will help people with lower numbers.

And many of the drugs used to treat high blood pressure carry risks, including dizziness and impaired kidney function. When doctors work to reduce the blood pressure of elderly patients too aggressively, for example, they put those patients at a “heightened risk for falls and fractures,” says Steven Nissen, M.D., chairman of cardiovascular medicine at the Cleveland Clinic.

Here, our experts’ advice on how to control your blood pressure in light of the new guidelines.

1. Know Your Blood Pressure Numbers

Even before the new recommendations were issued, 13 million Americans were walking around with undiagnosed high blood pressure, according to the Centers for Disease Control and Prevention.

And left unchecked, excessive pressure can damage blood vessels throughout the body and increase your risk for heart attacks, strokes, and heart failure as well as kidney damage, vision loss, and arterial blockages.

That’s why it’s important to detect high blood pressure early, so you can adjust course before the damage occurs.

Have your blood pressure checked at least once every two years, and more often if you’re 50 or older or have other risk factors for hypertension. For most people, it’s a good idea to have it done every time you visit a healthcare provider.

If your initial reading is elevated, don’t panic. That can be due to a number of factors, including stress or caffeine. (Read more about how to get accurate readings.) If your blood pressure is high and you have no history of high readings, your doctor may take another reading after about 5 minutes and, if that's still high, another in a couple of weeks to confirm.

It’s also a good idea to invest in a home blood pressure monitor. Sometimes, people who have high blood pressure at their doctor’s office actually have normal blood pressure in other settings, like at home, a condition known as “white-coat hypertension.” And if you are diagnosed with high blood pressure, a home monitor may help you get it under control, according to a study published in JAMA.  

2. Make Lifestyle Changes

If your blood pressure is over 120/80, lifestyle changes are in order, says Mary Norine Walsh, M.D., president of the American College of Cardiology and a cardiologist at St. Vincent Heart Center in Indianapolis.

A slightly elevated reading doesn’t mean that you are necessarily going to develop high blood pressure, or that you should consider medication, but it does mean you should make some broad-based lifestyle changes, Walsh says.

Regular exercise can lower your systolic pressure by up to 9 points, and losing 11 pounds can reduce it by 2.5 to 10 points. Avoiding excess sodium (anything beyond 2,400 mg in a day) can also lower it between 2 and 8 points in some people.  

3. Don't Rush to Drugs

Even if your blood pressure is elevated—above 130/90—you should generally try lifestyle changes first. 

Consumer Reports recommends considering drugs only if your blood pressure readings are over 140/90 for most adults and over 150/90 if you’re older than 60—and if several months of diet and lifestyle changes haven't sufficiently lowered your readings.

“One of the best prescriptions for high blood pressure is to adopt a healthy lifestyle,” Lipman says.

A combination of reduced sodium intake and the DASH diet (rich in fruits, vegetables, and whole grains, low or fat-free dairy, fish, poultry, beans, seeds and nuts), for example, dramatically lowers blood pressure in adults with hypertension, according to a Beth Israel Deaconess Medical Center study presented this month at the American Heart Association Scientific Sessions 2017 annual meeting.  

4. If You Do Need Drugs, Choose Carefully

Doctors use several different kinds of drugs to lower blood pressure, and for people with a reading above 150 it can take a combination to control the problem.

Still, it usually makes sense to start with the oldest, safest, and least expensive drug: diuretics, or water pills, such as chlorthalidone or hydrochlorothiazide.

These can drive up blood sugar levels, however, Nissen says, so if you have type 2 diabetes or are at risk of it, you may need to be monitored closely by your doctor or consider another drug, such as an ACE inhibitor or calcium channel blocker.  

5. If You Take BP Drugs, Check in Regularly With Your Doctor

One side effect of any blood pressure drug is dizziness, which can increase risk of falls, especially in older adults.

“It’s best to be super cautious, especially among the elderly," Nissen says. "I personally start with the lowest dose of medication possible and then reassess in a couple of weeks."

Individuals undergoing intensive blood pressure lowering are also more likely to experience a decline in kidney function, according to a study published earlier this month in the Clinical Journal of the American Society of Nephrology. That’s why it’s important to make sure that your physician periodically checks your kidney function and potassium levels, Lipman says.

If you’ve been on medication for a while and have gotten your blood pressure to target levels, consider talking to your doctor about lowering your dose, especially if you’ve implemented other lifestyle changes such as weight loss and exercise.