Blood pressure is the force exerted on your artery walls as blood flows through your body. Slightly elevated blood pressure is known as prehypertension. Left untreated, prehypertension is likely to progress to definite high blood pressure. Both prehypertension and high blood pressure increase your risk of heart attack, stroke and heart failure.
A blood pressure reading has two numbers. The first, or upper, number measures the pressure in your arteries when your heart beats (systolic pressure). The second, or lower, number measures the pressure in your arteries between beats (diastolic pressure). Normal blood pressure is below 120 systolic/80 diastolic as measured in millimeters of mercury (mm Hg). Prehypertension is a systolic pressure from 120 to 139 or a diastolic pressure from 80 to 89.
When prehypertension was defined as a new category of blood pressure in 2003, many people who thought they had normal blood pressure were surprised to learn that their blood pressure was now considered elevated. Why the new category? To reinforce the health risks of even slightly elevated blood pressure.
You can’t see or feel prehypertension, but there’s plenty you can do about it. Weight loss, exercise and other healthy lifestyle changes can often control prehypertension — and set the stage for a lifetime of better health.
Prehypertension doesn’t cause symptoms. In fact, even advanced high blood pressure may not cause symptoms.
The only way to detect prehypertension is to keep track of your blood pressure readings. Have your blood pressure checked at each doctor’s visit — or check it yourself at home with a home blood pressure monitoring device. Blood pressure measurements from a device in a pharmacy or other public location may not be accurate if the cuff isn’t the right size for you or if the device hasn’t been serviced regularly.
Any factor that increases pressure against the artery walls — including narrowing of the arteries and a greater than normal volume of blood — can lead to prehypertension. Sometimes an underlying condition causes blood pressure to rise, including:
- Sleep apnea
- Kidney disease
- Adrenal disease
- Thyroid disease
Certain medications — including birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs — also may cause blood pressure to rise. Illegal drugs, such as cocaine and amphetamines, can have the same effect.
Often, however, high blood pressure develops gradually over many years without a specific identifiable cause.
More than 30 percent of adults have prehypertension. A primary risk factor is being overweight. The greater your body mass, the more blood you need to supply oxygen and nutrients to your tissues. As the volume of blood circulated through your blood vessels increases, so does the force on your artery walls.
Prehypertension is more common in men than in women. Younger adults are more likely to have prehypertension than are older adults — probably because most older adults have progressed to high blood pressure. In fact, adults who are healthy at age 55 have a 90 percent chance of developing high blood pressure at some point in their lives, according to the American Heart Association.
Other risk factors may include:
- Family history of high blood pressure
- Sedentary lifestyle
- Diet high in sodium or low in potassium
- Tobacco use
- Excessive alcohol use
Certain chronic conditions — including high cholesterol, diabetes and sleep apnea — may increase the risk of prehypertension as well.
Normal blood pressure is below 120/80. Higher readings are classified as:
- Prehypertension — 120/80 to 139/89
- Stage 1 hypertension — 140/90 to 159/99
- Stage 2 hypertension — 160/100 or higher
Because blood pressure tends to fluctuate, a diagnosis of prehypertension is based on the average of two or more blood pressure readings taken on separate occasions in a consistent manner.
Prehypertension can damage your organs and increase the risk of heart attack, stroke and heart failure. And it tends to get worse over time. Within four years of being diagnosed with prehypertension, nearly one in three adults ages 35 to 64 and nearly one in two adults age 65 or older progress to definite high blood pressure, according to the American Heart Association.
As your blood pressure increases, so does your risk of cardiovascular disease. That’s why it’s so important to control prehypertension. The key is a commitment to healthy lifestyle changes.
- Eat healthy foods. Try the Dietary Approaches to Stop Hypertension (DASH) diet. Choose fruits, vegetables, whole grains and low-fat dairy foods. Eat less saturated fat and total fat.
- Maintain a healthy weight. If you’re overweight, losing even 5 pounds can lower your blood pressure.
- Reduce sodium intake. Limit the amount of sodium in your diet to no more than 2,400 milligrams a day — or even less. Remember that table salt, monosodium glutamate (MSG) and baking soda all contain sodium.
- Increase physical activity. Regular physical activity can help lower your blood pressure and keep your weight under control. Strive for at least 30 minutes of physical activity a day.
- Limit alcohol. If you choose to drink alcohol, do so in moderation — up to one drink a day for women, two drinks a day for men.
If you have prehypertension accompanied by diabetes, kidney disease or cardiovascular disease, your doctor may recommend blood pressure medication in addition to lifestyle changes. The benefits of medication for other adults with prehypertension are less clear. Although a 2006 study found that early medication and lifestyle changes can reduce the risk of eventually developing high blood pressure, the long-term effects of early medication are unknown.
The same healthy lifestyle changes recommended to treat prehypertension also help prevent high blood pressure. You’ve heard it before — eat healthy foods, exercise regularly, maintain a healthy weight, drink less alcohol. But take the advice to heart. Start adopting healthier habits today.