By Mayo Clinic Staff
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.
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.
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:
- 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 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.
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.
If you think you may have prehypertension or high blood pressure, make an appointment with your family doctor or health care provider to have your blood pressure checked.
No special preparations are necessary to have your blood pressure checked. You might want to wear a short-sleeved shirt to your appointment so that the blood pressure cuff can fit around your arm properly. You might want to avoid caffeinated food and drinks right before your test. You may want to use the toilet before having your blood pressure measured.
Because some medications — such as over-the-counter cold medicines, pain medications, antidepressants, birth control pills and others — can raise your blood pressure, it might be a good idea to bring a list of medications and supplements you take to your doctor's appointment. Don't stop taking any prescription medications that you think may affect your blood pressure without your doctor's advice.
Because appointments can be brief, and because there's often a lot to discuss, it's a good idea to be well-prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
- Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment. Prehypertension rarely has symptoms, but it's a risk factor for heart disease. Let your doctor know if you have any symptoms such as chest pain or shortness of breath.
- Write down key personal information, including a family history of high blood pressure, high cholesterol, heart disease, stroke or diabetes, and any major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements that you're taking.
- Take a family member or friend along, if possible. Sometimes it can be difficult to remember all of the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
- Be prepared to discuss your diet and exercise habits. If you don't already follow a diet or exercise routine, be ready to talk to your doctor about any challenges you might face in getting started.
- Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions ahead of time will help you make the most of your time together. List your questions from most important to least important in case time runs out. For prehypertension, some basic questions to ask your doctor include:
- What kinds of tests do I need?
- Do I need any medications?
- What foods should I eat or avoid?
- What's an appropriate level of physical activity?
- How often do I need to schedule appointments to check my blood pressure?
- Should I monitor my blood pressure at home?
- What are the alternatives to the primary approach that you're suggesting?
- I have these other health conditions. How can I best manage them together?
- Are there any restrictions that I need to follow?
- Should I see a specialist?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
- Do you have a family history of high cholesterol, high blood pressure or heart disease?
- What are your diet and exercise habits like?
- Do you drink alcohol? How many drinks do you have in a week?
- Do you smoke?
- When did you last have your blood pressure checked? What was your blood pressure measurement then?
What you can do in the meantime
It's never too early to make healthy lifestyle changes, such as quitting smoking, eating healthy foods and becoming more physically active. These are primary lines of defense against high blood pressure and its complications, including heart attack and stroke.
To diagnose prehypertension, you'll have a blood pressure test. Your doctor or a specialist will usually place an inflatable arm cuff around your arm and measure your blood pressure using 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).
Your blood pressure is considered normal if it's below 120/80 mm Hg. Other blood pressure measurements are categorized as:
- Prehypertension. Prehypertension is a systolic pressure ranging from 120 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg.
- Stage 1 hypertension. Stage 1 hypertension is a systolic pressure ranging from 140 to 159 mm Hg or a diastolic pressure ranging from 90 to 99 mm Hg.
- Stage 2 hypertension. More severe hypertension, stage 2 hypertension is a systolic pressure of 160 mm Hg or higher or a diastolic pressure of 100 mm Hg 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. Your blood pressure generally should be measured in both arms to determine if there is a difference. Your doctor may ask you to record your blood pressure at home and at work to provide additional information.
Your doctor may suggest a 24-hour blood pressure monitoring test called ambulatory blood pressure monitoring. The device used for this test measures your blood pressure at regular intervals over a 24-hour period and provides a more accurate picture of blood pressure changes over an average day and night. However, these devices aren't available in all medical centers, and they're rarely reimbursed.
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. Your doctor will likely suggest that you control prehypertension with lifestyle changes, such as:
- Maintaining a healthy weight or losing weight if you're overweight or obese
- Eating a healthy, low-salt diet
- Exercising regularly
- Limiting the amount of alcohol you drink
- Quitting smoking
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. Eat a healthy diet. Try the Dietary Approaches to Stop Hypertension (DASH) diet. Choose fruits, vegetables, whole grains, poultry, fish and low-fat dairy foods. Get plenty of potassium, which can help lower blood pressure. Eat less saturated fat and trans fat.
- Maintain a healthy weight. Keeping a healthy weight, or losing weight if you're overweight or obese, can help you control your blood pressure and lower your risk of related health problems. If you're overweight, losing even 5 pounds (2.3 kilograms) can lower your blood pressure.
Use less salt. The Dietary Guidelines for Americans recommend limiting sodium to less than 2,300 mg a day. A lower sodium level — 1,500 milligrams (mg) a day — is appropriate for people 51 years of age or older, and individuals of any age who are black or who have hypertension, diabetes or chronic kidney disease.
While you can reduce the amount of salt you eat by putting down the saltshaker, you usually should also pay attention to the amount of salt that's in the processed foods you eat, such as canned soups or frozen dinners.
Increase physical activity. Regular physical activity can help lower your blood pressure, manage stress, reduce your risk of other health problems and keep your weight under control.
For most healthy adults, the Department of Health and Human Services recommends that you get at least 150 minutes a week of moderate aerobic activity or 75 minutes a week of vigorous aerobic activity, or a combination or moderate and vigorous activity. Aim to do muscle-strengthening exercises at least two days a week.
- Limit alcohol. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger. One drink equals 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80-proof liquor.
- Don't smoke. Tobacco injures blood vessel walls and speeds up the process of hardening of the arteries. If you smoke, ask your doctor to help you quit.
- Manage stress. Reduce stress as much as possible. Practice healthy coping techniques, such as muscle relaxation, deep breathing or meditation. Getting regular physical activity and plenty of sleep can help, too.
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
- What is high blood pressure? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/hbp. Accessed May 6, 2015.
- AskMayoExpert. How is hypertension classified? Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.
- James PA, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: Report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA. 2014;311:507.
- Kaplan NM. Prehypertension. http://www.uptodate.com/home. Accessed May 6, 2015.
- U.S. Preventive Services Task Force. Screening for high blood pressure: U.S. Preventive Services Task Force reaffirmation recommendation statement. Annals of Internal Medicine. 2007;147:783.
- Kaplan NM, et al. Overview of hypertension in adults. http://www.uptodate.com/home. Accessed May 8, 2015.
- Understand your risk for high blood pressure. American Heart Association. http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/UnderstandYourRiskforHighBloodPressure/Understand-Your-Risk-for-High-Blood-Pressure_UCM_002052_Article.jsp. Accessed May 8, 2015.
- Kaplan NM, et al. Diet in the treatment and prevention of hypertension. http://www.uptodate.com/home. Accessed April 8, 2015.
- Dietary Guidelines for Americans, 2010. U.S. Department of Health and Human Services. http://www.cnpp.usda.gov/DGAs2010-PolicyDocument.htm. Accessed May 8, 2015.
- 2008 Physical Activity Guidelines for Americans. U.S. Department of Health and Human Services. http://www.health.gov/PAGUIDELINES/guidelines/default.aspx. Accessed May 8, 2015.
- Bushman B. Promoting exercise as medicine for prediabetes and prehypertension. Current Sports Medicine Reports. 2014;13:233.
- Collier SR, et al. Treatment of prehypertension: Lifestyle and/or medication. Vascular Health and Risk Management. 2012;8:613.
- Sheps SG. 5 Steps to Controlling High Blood Pressure. 2nd ed. Rochester, Minn.: Mayo Clinic; 2015.
- Ambulatory blood pressure monitoring and white coat hypertension in adults. http://www.uptodate.com/home. Accessed May 19, 2015.
- Sheps SG (expert opinion). Mayo Clinic, Rochester, Minn. May 19, 2015.