Prehypertension: A Little Too Much Pressure, A Lot of Trouble

August 12, 2014, 10:06am EDT

KEEPEveryone needs some blood pressure so that blood can get to all of the body’s organs. But how much is enough? How much is too much?

High blood pressure is often called the “silent killer,” because it usually doesn't cause symptoms. High blood pressure is also known as hypertension. It points to a higher risk of having heart disease, kidney disease and stroke. Doctors have known for a long time that blood pressure that is too high can cause these problems. But now doctors know that if it is even a little too high, it should be noticed.

When you visit a doctor for your annual checkup, your blood pressure will be taken. Blood pressure is measured by a machine with a band wrapped around your arm. The measure will tell if the blood pressure is normal, low, high, or somewhere in between. It is considered “prehypertension” when it doesn’t quite reach the level of high blood pressure, but it is higher than normal.

Prehypertension can serve as an early warning for patients and doctors. It is a sign of possible changes that could lead to heart disease. The pressure caused by constant prehypertension can change blood vessels and the heart in a damaging way. Prehypertension can also stress the kidneys.

A single blood pressure reading does not predict heart and blood vessel disease (also called cardiovascular disease). You won't be diagnosed with hypertension or prehypertension until it is high on several occasions. A blood pressure reading higher than normal will need to be carefully monitored.

The Rising Pressure

Americans’ blood pressure is rising. One study found that 65 million adults qualified for a hypertension diagnosis. It’s not just adults. Blood pressure levels have increased substantially for American children and teens, raising their risk of developing high blood pressure in adulthood. Blood pressure usually rises as we grow older.

Why does blood pressure become high? Some factors identified are having a family history of hypertension, being overweight, and eating a diet high in salt (sodium). And, problems with kidney function can cause high blood pressure. The opposite is also true. People with hypertension can develop chronic kidney disease (CKD). The kidney makes a hormone that helps regulate blood pressure. And, the kidney is damaged by slight increases in blood pressure that are sustained over time.

Hypertension is a risk factor for kidney disease. Doctors are beginning to suspect that prehypertension is too. About one out of six people with prehypertension in one study developed CKD. In this study, the people with prehypertension who developed chronic kidney disease were also often overweight or obese. Prehypertension often occurs in someone with several risks for heart disease. These are diabetes, cholesterol problems, chronic kidney disease, smoking, and coronary artery disease.

The larger your waist size, the more likely you are to have problems with high blood pressure, chronic kidney disease, or another heart disease risk factor. Just being overweight makes it more likely that you will develop hypertension. Overweight is also linked to chronic kidney disease.

How can you reduce these heart disease risks? You probably have heard the important steps before. Follow your doctor’s advice to the letter. Take every dose of every medicine you need. Make changes in your lifestyle. Lose weight if you are overweight. Make healthier food choices. Find ways to be more physically active. And, of course, refrain from smoking.

Heart disease is the leading cause of death worldwide. Anything you can do to help control these risk factors will pay off in reducing your risk of a heart attack or stroke. It might also help slow the effects of chronic kidney disease. You might feel perfectly healthy. But having high blood pressure or even slightly high blood pressure can mean you have a risk that is higher than someone with normal blood pressure. High blood pressure is a “silent killer.” There are no symptoms of this heart–damaging problem.

How many people have prehypertension? The latest study shows one out of three people. Talk to your doctor. Find out if your blood pressure is even a little high.

What Do the Blood Pressure Numbers Mean?

When blood pressure is measured, the result is given as two numbers, such as 120/80. The first number is the amount of force used when the heart beats (systolic blood pressure). The second number is the pressure in the arteries between heart beats (diastolic blood pressure). Pressures are measured in millimeters of mercury (mmHg). High blood pressure is defined as pressures above 140/90 for a period of time. Prehypertension is defined as a systolic pressure from 120–139 millimeters of mercury (mm Hg) or a diastolic pressure from 80–89 mm Hg. Because blood pressure changes often, your health care provider will check it on several different days before deciding whether your blood pressure is too high. Blood pressure is considered “high” when it is elevated above 140/90 for a period of time. For people with chronic kidney disease, the recommended level is below 130/80.

Can You Help Control Your Blood Pressure?

Yes, you can help. There are three things you can do: have a more active lifestyle, make healthy food choices, and, if needed, take your medicine every day as it is prescribed. With prehypertension, some people can bring blood pressure down to normal through weight loss, exercise and other changes for a healthy lifestyle. Medications are used to control high blood pressure. Medicines may be recommended for some people with prehypertension who also have other diseases, such as diabetes mellitus, chronic kidney disease and coronary artery disease.

If you have slightly high blood pressure, your doctor may suggest these steps:

  • lose weight if you are overweight,
  • get regular physical activity,
  • cut down on alcohol, and
  • change your food choices to those with less salt and fat

A special eating plan called “DASH” can help you lower your blood pressure. DASH stands for “Dietary Approaches to Stop Hypertension.” The DASH eating plan emphasizes fruits, vegetables, fat–free or low–fat milk and milk products, whole–grain products, fish, poultry, beans, seeds, and nuts. The DASH eating plan also contains less salt/sodium, sweets, added sugars, sugar containing beverages, fats, and red meats than the typical American diet.

Since fruits and vegetables are naturally lower in sodium than many other foods, DASH makes it easier to lower sodium in the diet. You can also use less salt when you cook and don't bring the salt shaker to the table. Remember, salt/sodium is found in many restaurant and fast-food meals, processed foods, such as soups, convenience meals from the freezer, some breads and cereals, and salted snacks. Your blood pressure is affected by what you eat.