| What is high blood pressure? |
High blood pressure (hypertension) is often called the silent killer because you can have it for years without knowing it. In fact, right now about 50 million Americans have high blood pressure, but about one-third (15 million) don't know it.
Blood pressure is determined by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. Your blood pressure normally varies during the day. It can even vary slightly with each beat of the heart. It increases during activity and decreases with rest.
Under new, stricter national blood pressure guidelines issued in May 2003, a resting blood pressure reading below 120/80 millimeters of mercury (mm Hg) is normal. If your resting blood pressure is consistently 140/90 mm Hg or higher, you have high blood pressure. A reading in between these levels places you in the prehypertensive category. Under the new guidelines, a reading of 115/75 is the level above which your risk of cardiovascular complications starts to increase.
Many people may not view a blood pressure above 115/75 as life-threatening because there are few, if any, symptoms. But uncontrolled high blood pressure can increase your risk of stroke, heart attack, heart failure and kidney failure. Fortunately, high blood pressure can be detected with a simple test — and once you know you have high blood pressure, you can work with your doctor to control it.
| Signs and symptoms |
Most people with high blood pressure have no signs or symptoms. Even so people often think that headaches, dizziness or nosebleeds are common warning signs of high blood pressure. It's true that a few people with early-stage high blood pressure have a dull ache in the back of their heads when they wake in the morning. Or perhaps they have a few more nosebleeds than normal.
Headaches, dizziness or nosebleeds typically don't occur until high blood pressure has advanced to a higher stage — one that's possibly life-threatening. Even so, most people with the highest blood pressure readings don't experience any of these symptoms.
Other conditions that can lead to uncontrolled high blood pressure cause the following signs and symptoms:
- Excessive perspiration
- Muscle cramps
- Weakness
- Frequent urination
- Rapid or irregular heartbeat (palpitations)
| Causes |
The more blood your heart pumps and the narrower your arteries, the higher your blood pressure. A blood pressure reading consists of two numbers:
- The top number indicates systolic pressure. This is the amount of pressure your heart generates when pumping blood out through your arteries.
- The bottom number indicates diastolic pressure. This is the amount of pressure in your arteries when your heart is at rest between beats.
In fact, some data indicate that 115/75 mm Hg should be the new gold standard. Once your blood pressure rises above that threshold, your risk of cardiovascular disease may begin to increase.
The new guidelines also include a category called prehypertension. Prehypertension is a systolic pressure ranging from 120 to 139 or a diastolic pressure ranging from 80 to 89. So, under these new classification criteria, if your blood pressure is right at 120/80, you have prehypertension — your blood pressure isn't normal or optimal.
And you can have prehypertension even if just one of the two numbers in your blood pressure reading is elevated. For instance, if your systolic pressure seems fine at 118 but your diastolic pressure is 84, you have prehypertension.
The guidelines include this category to underscore the increasing health risks as your blood pressure rises.
As before, the new guidelines classify blood pressure as outright hypertension beginning at 140/90 mm Hg. But the new guidelines do away with the old, more complicated system of categorizing hypertension into three risk groups called A, B and C based on three stages of hypertension, plus such factors as your sex and other health problems you may have. Instead, hypertension now simply falls into two categories:
- Stage 1. This includes a systolic pressure ranging from 140 to 159 or a diastolic pressure ranging from 90 to 99.
- Stage 2. The most severe hypertension, this includes a systolic pressure of 160 or higher or a diastolic pressure of 100 or higher.
The guidelines were issued in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC) and published in the Journal of the American Medical Association in May 2003. The JNC represents a coalition of leaders from 46 professional, public, voluntary and federal health care agencies, including the American College of Cardiology, the American Diabetes Association, the American Heart Association, the American Public Health Association, the American Society of Hypertension, and the National Heart, Lung, and Blood Institute.
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Source: Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure, 2003. Numbers are expressed in millimeters of mercury (mm Hg).
No matter what category your blood pressure falls under, adopting healthy lifestyle habits can help keep it under control. Once your blood pressure rises above 115/75 millimeters of mercury, your risk of cardiovascular complications starts to increase.
It's not always possible to determine why blood pressure reaches higher levels in some people. In fact, doctors identify a specific disease or cause in less than 1 case in 20. When a cause cannot be determined, high blood pressure is called essential hypertension or primary hypertension.
When a cause is determined, the increased pressure is called secondary hypertension. This means that the increased pressure results from another cause such as:
- Medications, which include birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs
- Kidney disease
- Adrenal disease
- Thyroid disease
- Abnormal blood vessels
- Preeclampsia, a significant increase in blood pressure during the last 3 months of pregnancy
- Use of illegal drugs, such as cocaine and amphetamines
- Sleep apnea
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| Risk factors |
There are four major risk factors of high blood pressure that you cannot control. They are:
- Age. Your risk of high blood pressure increases as you get older.
- Race. If you're black, you're twice as likely to develop high blood pressure than if you
are white. You're also more likely to develop serious complications from the disease or to die of a
stroke or heart attack related to your high blood pressure. In addition, some populations of American
Indians have a higher prevalence of high blood pressure than whites.
- Sex. In young adulthood and early middle age, men have high blood pressure more often than
women do. For men and women ages 55 to 64, rates are about equal. At ages 65 and older, rates for
women surpass those for men.
- Family history. High blood pressure tends to run in families.
- Obesity. The more body mass you have, the more blood you need to supply oxygen and
nutrients to your tissues. The volume of blood circulated through your blood vessels increases and
creates extra force on your artery walls.
- Inactivity. Lack of physical activity increases your risk of high blood pressure by
increasing your risk of being overweight. Inactive people also tend to have higher heart rates. Their
heart muscles have to work harder with each contraction, increasing the force on the arteries.
- Tobacco use. The chemicals in tobacco can damage the lining of your artery walls, causing
the arteries to accumulate fatty deposits that contain cholesterol (plaques). Nicotine also constricts
your blood vessels and forces your heart to work harder.
- Sodium sensitivity and salt intake. People who are sodium sensitive retain sodium more
easily, leading to fluid retention and increased blood pressure.
- Low potassium intake. Potassium is a mineral that helps balance the amount of sodium in
your cells. If you don't consume or retain enough potassium, you can accumulate too much sodium.
- Excessive alcohol. Exactly how or why alcohol increases blood pressure isn't understood.
But over time, heavy drinking can damage your heart muscle.
- Stress. High levels of stress can lead to a temporary but dramatic increase in blood pressure. Stress also can promote high blood pressure if you then try to relax by eating more, using more nicotine or drinking more alcohol.
High blood pressure in children, more often than in adults, indicates that something else is wrong and the increase in blood pressure is a sign of that condition. In general, high blood pressure in children is uncommon. However, as an increasing number of children become less physically active and more obese, a greater percentage of them may run the risk of developing high blood pressure during their teens.
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| When to seek medical advice |
Have your blood pressure checked at least every 2 years. Your doctor may ask to check your blood pressure more often. The National Institutes of Health recommends having your blood pressure checked more often than every 2 years if your blood pressure is above normal.
The interval at which you should have your blood pressure rechecked depends not only on your most recent blood pressure reading, but also your past blood pressure readings, your other risk factors for heart disease and the presence of other diseases. See your doctor for advice.
For years health professionals tended to focus on diastolic pressure, which is the bottom number. The theory was this: The body can tolerate occasional increases in systolic pressure, but diastolic pressure that stays consistently high can lead to organ damage. But this theory has been revised. A high systolic reading is an equally important, if not more serious, warning sign of potential health risks.
In fact many people, particularly older Americans, have a normal diastolic level but an elevated systolic level. This type of high blood pressure — isolated systolic hypertension (ISH) — is actually the most common. Systolic pressure is a better predictor of the risks of high blood pressure. In people older than 55, the pulse pressure — the difference between the systolic and diastolic pressures — is an important predictor of health risks as well.
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| Screening and diagnosis |
High blood pressure is most often discovered during a routine physical examination. Fortunately, diagnosing high blood pressure is relatively simple. It involves measuring your blood pressure periodically over several weeks or months to see if the reading remains high.
Blood pressure is taken with an inflatable arm cuff connected to a pressure-measuring unit — a device called a manometer (sphygmomanometer). Your blood pressure generally isn't considered high unless the average of three pairs of readings in a row is elevated, each pair taken at different visits to your doctor under similar conditions.
Everyone's blood pressure normally varies through the day. And some people have a rise in blood pressure especially during visits to a doctor — a phenomenon known as white-coat hypertension. That's why it's important to take more than one reading and on more than one occasion. Your doctor may ask you to record your blood pressure at home and work to provide additional data.
Your doctor is also likely to do the following:
- Ask you questions about your health and your family's health (a health history).
- Do a physical examination.
- Ask you to have routine tests such as urine test (urinalysis), a blood test or an electrocardiogram (ECG), which measures your heart's electrical activity.
- Consider the need for more specialized tests to examine blood flow. These tests may include ultrasonography, magnetic resonance angiography, angiography, computerized tomography (CT), magnetic resonance imaging (MRI) or nuclear scanning. They're especially important if your doctor is looking for secondary causes of hypertension.
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| Complications |
If you have high blood pressure, you need to control it. Over time excessive force on your artery walls can seriously damage many of your body's vital organs. The higher your blood pressure or the longer it goes uncontrolled, the greater the damage can be. By the time symptoms appear, you may already have an injury.
Many studies demonstrate a direct relationship between uncontrolled high blood pressure and increased risk of stroke, heart attack, heart failure, kidney failure and eye problems. More specifically, high blood pressure can lead to the following problems:
- Damage to your arteries. This can result in hardening and thickening of the arteries (arteriosclerosis), deposits of fat in the artery linings (atherosclerosis) and an enlarged, bulging blood vessel (aneurysm).
- Thickening of the heart's main pumping chamber. Called left ventricular hypertrophy, this can eventually lead to heart failure. The heart muscle thickens in order to pump blood against the higher pressure in the vessels. More blood is needed to do to this, but narrowed blood vessels cannot supply that blood. At the same time, the thickened muscle may have a hard time pumping enough blood to meet your body's needs, causing fluid to build up in your lungs or in your feet and legs.
- A blocked or ruptured blood vessel in your brain. This can lead to stroke. High blood pressure is the most important risk factor for a stroke.
- Weakened and narrowed blood vessels in your kidneys. This can prevent these organs from functioning normally.
- Thickened, narrowed or torn blood vessels in the eyes. This can result in vision loss.
To reduce your risk of these complications, take action now. The results can be dramatic. Controlling your blood pressure for five years or more greatly decreases your risk of stroke, heart attack and heart failure. It may also reduce your risk of dementia.
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| Treatment |
The goal of treatment is to prevent health complications that may occur as a result of high blood pressure. Your doctor also may suggest steps to control disorders such as diabetes and high blood cholesterol that may contribute to high blood pressure.
Blood pressure goals aren't the same for everyone. Although everyone should strive to reach blood pressure readings of below 140/90, doctors recommend lower goals for people with certain conditions. The goal is 130/80 if you have or have had heart failure, mild kidney failure, a heart attack, a stroke, a transient ischemic attack or diabetes. The goal is 120/75 if you have moderate or severe kidney failure.
The safest way to control your blood pressure is to change your lifestyle. But sometimes lifestyle changes alone can't reduce your blood pressure enough. You may also have to treat another medical condition besides high blood pressure. In these cases, you may need medication. Discuss with your doctor the goals of treatment and the roles that both lifestyle changes and medications can play. Maintaining lifestyle changes may improve the effectiveness of the medications you're taking and may mean you'll need fewer drugs or lower dosages.
Many types of medications to lower blood pressure are available. They lower your blood pressure in different ways. If one medication doesn't decrease your blood pressure to a safe level, your doctor may substitute another one or add one to your regimen.
The major types of medication first chosen to control high blood pressure include:
- Diuretics. These medications act on your kidneys to help your body eliminate sodium and
water, reducing blood volume. If you're an older adult or black and have high blood pressure, a
diuretic is often the first (but not only) choice in treatment because it's often the most effective.
- Beta blockers. These medications block the effects of certain adrenaline-related chemicals,
causing your heart to beat more slowly and less forcefully.
- Angiotensin-converting enzyme (ACE) inhibitors. These medications help relax blood vessels
by blocking the formation of a naturally occurring chemical that narrows blood vessels. These
medications are especially important in treating high blood pressure in people with coronary heart
disease, heart failure or kidney failure.
- Angiotensin II receptor blockers. These medications help relax blood vessels by blocking
the action — not the formation — of a naturally occurring chemical that narrows blood vessels.
- Calcium antagonists, also known as calcium channel blockers (CCBs). These medications help relax the muscles of blood vessels. Some slow your heart rate. Note: If you take a calcium antagonist, don't combine taking the drug with eating grapefruit or drinking grapefruit juice. Grapefruit juice interacts with calcium antagonists, causing blood levels of the medication to rise and putting you at a higher risk of side effects from the drug. This action of the juice may persist for 24 hours.
Other drug classes may be used in addition to combinations of the above medications, when blood pressure hasn't reached a set goal level. These drug classes may include:
- Alpha blockers. These medications prevent muscle contractions in smaller arteries and
reduce the effects of naturally occurring body chemicals that narrow blood vessels.
- Central-acting agents. These medications prevent your brain from signaling your nervous
system to increase your heart rate and narrow your blood vessels.
- Direct vasodilators. These medications work directly on the muscles in the walls of your arteries, preventing the muscles from tightening and your arteries from narrowing.
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| Self-Care |
The best strategy for controlling and preventing high blood pressure is to begin with lifestyle changes. This is true even if you're taking medication to reduce high blood pressure. You may require higher dosages of medication than otherwise needed if you don't make certain changes in your habits. Here's what you can do:
- Eat for health. Make sure you eat a nutritionally balanced diet. Emphasize plenty of
grains, fruits, vegetables and low-fat dairy foods. A 1997 study called Dietary Approaches to Stop
Hypertension (DASH) indicates that such a diet can promote weight loss and help to lower blood
pressure. Limiting sodium in combination with other lifestyle changes reduces blood pressure further
and may be enough to keep you off medication. Even if you take blood pressure medication, limiting
sodium can help the medication be more effective. If you're at risk for high blood pressure, limiting
sodium may help prevent the condition. This lifestyle change is safe and reasonable for just about
anyone who is otherwise healthy and eats well. If you're unsure about the best way to shop for foods
or prepare foods with lower levels of sodium, consult with your doctor or a registered dietitian. Read
food labels. Most Americans' daily salt intake comes from prepared or processed foods, so cutting back
on those types of foods is a good place to start. Restricting your sodium intake to below 1, 500
milligrams (mg) a day significantly lowers blood pressure. The average adult needs 500 mg of sodium a
day to replace losses.
- Achieve a healthy weight. If your body mass index (BMI) is 25 or more, lose weight. Losing
as few as 10 pounds may reduce your blood pressure significantly. For some people weight loss alone is
enough to avoid blood pressure medication. Being overweight can constitute a more serious risk factor
for health problems depending on how you carry the extra weight. If you carry most of your fat around
your waist or upper body, you may be referred to as apple-shaped. If you carry most of your fat around
your hips and thighs or lower body, you may be referred to as pear-shaped. Generally, when it comes to
your health, it's better to have the shape of a pear than the shape of an apple. If you have an apple
shape — a potbelly or spare tire — you carry more fat in and around your abdominal organs. Fat in your
abdomen increases your risk of many of the serious conditions associated with obesity. Women's waist
measurement should fall below 35 inches. Men's should be less than 40 inches.
- Exercise. Regular aerobic exercise seems to lower blood pressure in some people, even
without weight loss. For example, vigorous walking for 30 minutes most days of the week will lower
blood pressure and help with weight loss. Instead of meeting for lunch, decide to take a walk for your
health.
- Don't smoke. If you have high blood pressure, using tobacco can lead to more cholesterol
and other fatty deposits in your arteries (atherosclerosis) and promote the constriction of your blood
vessels. Smoking one cigarette raises your blood pressure for about an hour, so if you smoke 10 or
more cigarettes a day, your blood pressure is elevated for most of the day.
- Limit alcohol and caffeine. Even if you're healthy, alcohol and caffeine can raise your
blood pressure to an unhealthy level. Reducing your consumption of alcohol can reduce your blood
pressure. If you cut back to a moderate level of alcohol consumption, you can lower your systolic
pressure by about 5 points and your diastolic pressure by about 3 points. If you're a medium- or
large-framed man younger than age 65, moderate drinking means no more than two drinks a day. That's
two 12-ounce beers, two 5-ounce glasses of wine or two 1-ounce shots of 100-proof whiskey. If you're a
woman, a small-framed man or older than age 65, moderate drinking means no more than one drink a day.
Caffeine is a mild stimulant that can fight fatigue, boost concentration and lighten your mood. But it
may also increase your blood pressure. If you have high blood pressure, limit daily caffeine to no
more than 2 cups of coffee, 3 or 4 cups of tea, or 2 to 4 cans of caffeinated soda. In addition, avoid
caffeine right before activities that naturally increase your blood pressure, such as exercise or hard
physical labor.
- Manage stress. The effects of stress usually are only temporary. But if you experience
stress regularly, it can produce increases in blood pressure that can — over time — damage your
arteries, heart, brain, kidneys and eyes. You can avoid and better cope with stress by making changes
in your normal routine and by developing relaxation techniques. You may be able to make your daily
routine less stressful by doing such things as getting organized, simplifying your schedule,
maintaining good social relationships, practicing positive thinking and scheduling daily "worry time"
or dedicated time for solving or thinking about your problems. Relaxation techniques may include deep
breathing exercises, muscle relaxation exercises, guided imagery, meditation and biofeedback.
- Get plenty of sleep. When you're refreshed, you're better able to tackle the next day's problems, allowing you to avoid and better cope with stress. Going to sleep and awakening at a consistent time each day can help you sleep well. A bedtime ritual such as taking a warm bath, reading or eating a snack helps many people relax. See your doctor if your blood pressure hasn't decreased after 3 to 6 months of lifestyle changes. Your doctor may prescribe medication that can be used in conjunction with healthy changes in your diet and exercise habits.
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Source: Seventh Report of the Joint National committee on Prevention, Detection, Evaluation and Treatment of high blood pressure, 2003.
Adopting healthy lifestyle habits goes far in controlling and reducing your blood pressure. Here's how five basic changes in your lifestyle can benefit your blood pressure.
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| Coping skills |
High blood pressure isn't a problem that you can treat and then ignore. This is a condition you need to manage for the rest of your life.
Coping with high blood pressure includes a wide spectrum of activities. Steps you can take include:
- Measure your blood pressure at home. Your blood pressure measured at home usually is lower
than it would be at your doctor's office. If your goal is to average less than 140/90 in your doctor's
office, your corresponding target at home is 135/85. Ask your doctor for advice in buying a device to
monitor blood pressure and regarding correct cuff size. Ask your doctor to validate the device when
it's new and annually so that you can better trust the numbers. It's best to monitor your blood
pressure several times during the day — such as morning, evening, before eating and 2 hours after
eating. Take it (and record it) twice each time. It's not necessary to do this more than once a week
if your blood pressure is controlled, but ask your doctor about the schedule you should follow. If you
exercise during the day, your blood pressure likely will be lower for a long time after you have
stopped exercising. Therefore, it's best to measure it before exercising.
- Take your medications properly. If side effects or costs pose problems, talk with your
doctor instead of discontinuing your medications.
- Manage stress. Get more sleep, learn to say no to extra tasks, release negative thoughts
and maintain good relationships, and remain patient and optimistic.
- Make regular visits to your doctor. It takes a team effort to treat high blood pressure
successfully. Your doctor can't do it alone, and neither can you. The two of you need to work together
to bring your blood pressure down to a safe level — and keep it there.
- Adopt positive health habits. This includes eating a healthy diet, losing weight, exercising, not smoking, and limiting alcohol and caffeine intake.
Educating your family and friends is important in helping you cope. When people don't understand the danger of uncontrolled high blood pressure, they can unintentionally work against you. For example they might offer you unhealthful food or complain about the cost of your medicine.
When family and friends fully understand that uncontrolled high blood pressure threatens your life, they'll encourage you to take your medicine, eat well and go for your daily walk.
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— May 15, 2003 —