Overview

Slightly elevated blood pressure is known as prehypertension. Prehypertension will likely turn into high blood pressure (hypertension) unless you make lifestyle changes, such as getting more exercise and eating healthier foods. 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.

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, severe 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.

When to see a doctor

Ask your doctor for a blood pressure reading at least once every two years starting at age 18. 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 can lead to prehypertension. Atherosclerosis, which is the buildup of fatty deposits in your arteries, can lead to high blood pressure. Sometimes an underlying condition causes blood pressure to rise. Possible conditions that can lead to prehypertension or high blood pressure include:

  • Atherosclerosis
  • Obstructive 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. 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.

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. Many older adults have progressed to high blood pressure, and the risk of high blood pressure increases as you age.
  • Sex. Prehypertension is more common in men than in women. Through early middle age, or about age 45, high blood pressure is more common in men. Women are more likely to develop high blood pressure after age 65.
  • Race. High blood pressure is particularly common among blacks, often developing at an earlier age than it does in whites.
  • Family history of high blood pressure. High blood pressure tends to run in families. If a first-degree relative, such as a parent or sibling, has high blood pressure, you're more likely to develop the condition.
  • Not being physically active. Not exercising can increase your risk of high blood pressure and increase your risk of being overweight.
  • Diet high in salt (sodium) or low in potassium. Sodium and potassium are two key nutrients in the way your body regulates your blood pressure. If you have too much sodium or too little potassium in your diet, you're more likely to have high blood pressure.
  • Tobacco use. Smoking cigarettes, chewing tobacco or even being around other people who are smoking (secondhand smoke) can increase your blood pressure.
  • Drinking too much alcohol. Drinking more than two drinks a day if you're a man age 65 or younger or more than one drink a day if you're a woman of any age or a man older than age 65 can increase your blood pressure. One drink equals 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80-proof liquor.
  • Certain chronic conditions. Certain chronic conditions — including kidney disease, diabetes and sleep apnea — may increase the risk of prehypertension.

Although prehypertension and high blood pressure are most common in adults, children may be at risk, too. For some children, high blood pressure is caused by problems with the kidneys or heart. But for a growing number of kids, poor lifestyle habits, such as an unhealthy diet, obesity and lack of exercise, contribute to prehypertension and high blood pressure.

Complications

Prehypertension itself doesn't often have complications. If you have prehypertension, it's likely to worsen and develop into high blood pressure (hypertension). The term "prehypertension" is often used by doctors to signal that it's time to begin making lifestyle changes or, if you have certain conditions such as diabetes, to consider taking medications to stop your blood pressure from rising to definite high blood pressure.

High blood pressure can damage your organs and increase the risk of several conditions including heart attack, heart failure, stroke, aneurysms and kidney failure.

Prevention

The same healthy lifestyle changes recommended to treat prehypertension also help prevent high blood pressure. You've heard it before — eat healthy foods, use less salt, exercise regularly, maintain a healthy weight, drink less alcohol and quit smoking. But take the advice to heart. Start adopting healthier habits today.

June 23, 2015
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