Prehypertension

Definition

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 will likely turn into 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). Prehypertension is a systolic pressure from 120 to 139 millimeters of mercury (mm Hg) or a diastolic pressure from 80 to 89 mm Hg.

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.

Symptoms

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.

When to see a doctor
Ask your doctor for a blood pressure reading at least once every two years. You may need more frequent readings if you have prehypertension or other risk factors for cardiovascular disease.

Causes

Any factor that increases pressure against the artery walls — including atherosclerosis, the 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 temporarily rise. Illicit 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.

Risk factors

Risk factors for prehypertension include:

• Being overweight or obese. 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.
• Age. 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.
• Sex. Prehypertension is more common in men than in women.
• 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.

Complications

Prehypertension itself doesn't often have complications. If you have prehypertension, it's likely to worsen and become hypertension. The term "prehypertension" is often used by doctors to signal that it's time to begin making lifestyle changes or taking medications to stop your blood pressure from rising.

Prehypertension that leads to hypertension 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 end up with high blood pressure, according to the American Heart Association.

Tests and diagnosis

Blood pressure is measured with an inflatable arm cuff and a pressure-measuring gauge. A blood pressure reading, given in millimeters of mercury (mm Hg), 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 120/80. 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.

Treatments and drugs

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.

Lifestyle and home remedies

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.

Prevention

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.