Most people with high blood pressure have no signs or symptoms, even if blood pressure readings reach dangerously high levels.

Although a few people with early-stage high blood pressure may have dull headaches, dizzy spells or a few more nosebleeds than normal, these signs and symptoms typically don't occur until high blood pressure has reached an advanced — even life-threatening — stage.

When to see a doctor
Unless you have symptoms of extremely high blood pressure, there's probably no need to make a special trip to the doctor to have your blood pressure checked. You'll likely have your blood pressure taken as part of a routine doctor's appointment.

Ask your doctor for a blood pressure reading at least every two years starting at age 20. He or she will likely recommend more frequent readings if you've already been diagnosed with high blood pressure, prehypertension or other risk factors for cardiovascular disease. Children age 3 and older will usually have their blood pressure measured as a part of their yearly checkups.

If you don't regularly see your doctor, but are concerned about your blood pressure, you may be able to get a free blood pressure screening at a health resource fair or other locations in your community. You can also find machines in drugstores that will measure your blood pressure for free, but these machines aren't often calibrated and can give you inaccurate results.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

There are two types of high blood pressure.

Primary (essential) hypertension
In 90 to 95 percent of high blood pressure cases in adults, there's no identifiable cause. This type of high blood pressure, called essential hypertension or primary hypertension, tends to develop gradually over many years.

Secondary hypertension
The other 5 to 10 percent of high blood pressure cases are caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension. Various conditions and medications can lead to secondary hypertension, including:

• Kidney abnormalities
• Tumors of the adrenal gland
• Certain congenital heart defects
• Certain medications, such as birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs
• Illegal drugs, such as cocaine and amphetamines

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

High blood pressure has many risk factors. Some you can't control. High blood pressure risk factors include:

• Age. The risk of high blood pressure increases as you age. Through early middle age, high blood pressure is more common in men. Women are more likely to develop high blood pressure after menopause.
• Race. High blood pressure is particularly common among blacks, often developing at an earlier age than it does in whites. Serious complications, such as stroke and heart attack, also are more common in blacks.
• Family history. High blood pressure tends to run in families.

Other risk factors for high blood pressure are within your control.

• Being overweight or obese. The more you weigh, 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 pressure on your artery walls.
• Not being physically active. People who are inactive tend to have higher heart rates. The higher your heart rate, the harder your heart must work with each contraction — and the stronger the force on your arteries. Lack of physical activity also increases the risk of being overweight.
• Using tobacco. Not only does smoking tobacco immediately raise your blood pressure temporarily, but the chemicals in tobacco can damage the lining of your artery walls. This can cause your arteries to narrow, increasing your blood pressure.
• Too much salt (sodium) in your diet. Too much sodium in your diet can cause your body to retain fluid, which increases blood pressure.
• Too little potassium in your diet. Potassium helps balance the amount of sodium in your cells. If you don't consume or retain enough potassium, you may accumulate too much sodium in your blood.
• Too little vitamin D in your diet. It's uncertain if having too little vitamin D in your diet can lead to high blood pressure. Researchers think vitamin D may affect an enzyme produced by your kidneys that affects your blood pressure. More studies are necessary to determine vitamin D's role in blood pressure.
• Drinking too much alcohol. Over time, heavy drinking can damage your heart. Having more than two or three drinks in a sitting can also temporarily raise your blood pressure, as it may cause your body to release hormones that increase your blood flow and heart rate.
• Stress. High levels of stress can lead to a temporary, but dramatic, increase in blood pressure. If you try to relax by eating more, using tobacco or drinking alcohol, you may only increase problems with high blood pressure.
• Certain chronic conditions. Certain chronic conditions also may increase your risk of high blood pressure, including high cholesterol, diabetes, kidney disease and sleep apnea.

Sometimes pregnancy contributes to high blood pressure, as well.

Although high blood pressure is 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 and lack of exercise — contribute to high blood pressure.

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The excessive pressure on your artery walls caused by high blood pressure can damage your blood vessels, as well as organs in your body. The higher your blood pressure and the longer it goes uncontrolled, the greater the damage.

Uncontrolled high blood pressure can lead to:

• Damage to your arteries. This can result in hardening and thickening of the arteries (atherosclerosis), which can lead to a heart attack, stroke or other complications.
• Aneurysm. Increased blood pressure can cause your blood vessels to weaken and bulge, forming an aneurysm. If an aneurysm ruptures, it can be life-threatening.
• Heart failure. To pump blood against the higher pressure in your vessels, your heart muscle thickens. Eventually, the thickened muscle may have a hard time pumping enough blood to meet your body's needs, which can lead to heart failure.
• A blocked or ruptured blood vessel in your brain. High blood pressure in the arteries leading to your brain can either slow the blood flow to your brain or cause a blood vessel in your brain to burst, causing 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.
• Metabolic syndrome. This syndrome is a cluster of disorders of your body's metabolism — including increased waist circumference, high triglycerides, low high-density lipoprotein (HDL), or "good," cholesterol, high blood pressure, and high insulin levels. If you have high blood pressure, you're more likely to have other components of metabolic syndrome. The more components you have, the greater your risk of developing diabetes, heart disease or stroke.
• Trouble with memory or understanding. Uncontrolled high blood pressure also may affect your ability to think, remember and learn. Trouble with memory or understanding concepts is more common in people who have high blood pressure.

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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.

Because some medications — such as over-the-counter cold medicines, 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.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

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).

The latest blood pressure guidelines, issued in 2003 by the National Heart, Lung, and Blood Institute, divide blood pressure measurements into four general categories:

• Normal blood pressure. Your blood pressure is normal if it's below 120/80 mm Hg. However, some doctors recommend 115/75 mm Hg as a better goal. Once blood pressure rises above 115/75 mm Hg, the risk of cardiovascular disease begins to increase.
• Prehypertension. Prehypertension is a systolic pressure ranging from 120 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg. Prehypertension tends to get worse over time. Within four years of being diagnosed with prehypertension, nearly one-third of adults ages 35 to 64 and nearly half the adults age 65 or older develop high blood pressure.
• 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. The most 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.

Both numbers in a blood pressure reading are important. But after age 50, the systolic reading is even more significant. Isolated systolic hypertension (ISH) — when diastolic pressure is normal but systolic pressure is high — is the most common type of high blood pressure among people older than 50.

Your doctor will likely take two to three blood pressure readings each at two or more separate appointments before diagnosing you with high blood pressure. This is because blood pressure normally varies throughout the day — and sometimes specifically during visits to the doctor, a condition called white-coat hypertension. Your doctor may ask you to record your blood pressure at home and at work to provide additional information. Measuring your blood pressure at home can also help diagnose masked hypertension, a condition in which your blood pressure is lower than it normally is when you visit the doctor's office.

If you have any type of high blood pressure, your doctor may recommend routine tests, such as a urine test (urinalysis), blood tests and an electrocardiogram (ECG) — a test that measures your heart's electrical activity. More extensive testing isn't usually needed, at least initially.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Your blood pressure treatment goal depends on how healthy you are.

* Although 120/80 mm Hg or lower is the ideal blood pressure goal, doctors are unsure if you need treatment (medications) to reach that level.

If you're an adult age 80 or older and your blood pressure is very high, your doctor may set a target blood pressure goal for you that's slightly higher than 140/90 mm Hg.

Changing your lifestyle can go a long way toward controlling high blood pressure. But sometimes lifestyle changes aren't enough. In addition to diet and exercise, your doctor may recommend medication to lower your blood pressure. Which category of medication your doctor prescribes depends on your stage of high blood pressure and whether you also have other medical problems.

The major types of medication used to control high blood pressure include:

• Thiazide diuretics. Diuretics, sometimes called "water pills," are medications that act on your kidneys to help your body eliminate sodium and water, reducing blood volume. Thiazide diuretics are often the first — but not the only — choice in high blood pressure medications. Still, diuretics are often not prescribed. If you're not taking a diuretic and your blood pressure remains high, talk to your doctor about adding one or replacing a drug you currently take with a diuretic.

  If you're age 80 or older, a special type of thiazide diuretic, indapamide (Lozol), may be particularly effective in lowering your blood pressure. In this age group, indapamide has been shown to reduce deaths from stroke, heart failure and other cardiovascular disease causes.

• Beta blockers. These medications reduce the workload on your heart and open your blood vessels, causing your heart to beat slower and with less force. When prescribed alone, beta blockers don't work as well in blacks — but they're effective when combined with a thiazide diuretic.
• Angiotensin-converting enzyme (ACE) inhibitors. These medications help relax blood vessels by blocking the formation of a natural chemical that narrows blood vessels. ACE inhibitors may be especially important in treating high blood pressure in people with coronary artery disease, heart failure or kidney failure. Like beta blockers, ACE inhibitors don't work as well in blacks when prescribed alone, but they're effective when combined with a thiazide diuretic.
• Angiotensin II receptor blockers. These medications help relax blood vessels by blocking the action — not the formation — of a natural chemical that narrows blood vessels. Like ACE inhibitors, angiotensin II receptor blockers often are useful for people with coronary artery disease, heart failure and kidney failure.
• Calcium channel blockers. These medications help relax the muscles of your blood vessels. Some slow your heart rate. Calcium channel blockers may work better for blacks than do ACE inhibitors or beta blockers alone. A word of caution for grapefruit lovers, though. Grapefruit juice interacts with some calcium channel blockers, increasing blood levels of the medication and putting you at higher risk of side effects. Talk to your doctor or pharmacist if you're concerned about interactions.
• Renin inhibitors. Aliskiren (Tekturna) slows down the production of renin, an enzyme produced by your kidneys that starts a cascade of chemical steps that increases blood pressure. Tekturna works by reducing the ability of renin to begin this process. The drug is still being studied to figure out its ideal use and dosage for people with high blood pressure.

If you're having trouble reaching your blood pressure goal with combinations of the above medications, your doctor may prescribe:

• Alpha blockers. These medications reduce nerve impulses to blood vessels, reducing the effects of natural chemicals that narrow blood vessels.
• Alpha-beta blockers. In addition to reducing nerve impulses to blood vessels, alpha-beta blockers slow the heartbeat to reduce the amount of blood that must be pumped through the vessels.
• Central-acting agents. These medications prevent your brain from signaling your nervous system to increase your heart rate and narrow your blood vessels.
• Vasodilators. These medications work directly on the muscles in the walls of your arteries, preventing the muscles from tightening and your arteries from narrowing.

Once your blood pressure is under control, your doctor may have you take a daily aspirin to reduce your risk of cardiovascular disorders.

To reduce the number of daily medication doses you need, your doctor may prescribe a combination of low-dose medications rather than larger doses of one single drug. In fact, two or more blood pressure drugs often work better than one. Sometimes finding the most effective medication — or combination of drugs — is a matter of trial and error.

Resistant hypertension: When your blood pressure is difficult to control
If your blood pressure has remained stubbornly high despite taking at least three different types of high blood pressure drugs, one of which should be a diuretic, you may have resistant hypertension. Resistant hypertension is blood pressure that's resistant to treatment. People who have controlled high blood pressure but are taking four different types of medications at the same time to achieve that control also are considered to have resistant hypertension.

Having resistant hypertension doesn't mean your blood pressure will never get lower. In fact, if you and your doctor can identify what's behind your persistently high blood pressure, there's a good chance you can meet your goal with the help of treatment that's more effective. You may need to see a hypertension specialist if your primary care doctor isn't able to pinpoint a cause. It may also be that another condition you have that you may not be aware of, such as sleep apnea or kidney problems, is causing your high blood pressure. You may need to be more aggressive in following lifestyle recommendations.

Your doctor or hypertension specialist can evaluate whether the medications and doses you're taking for your high blood pressure are appropriate. You may have to fine-tune your medications to come up with the most effective combination and doses. Your doctor may also prescribe other medications, including a more potent or longer acting diuretic if you're not already taking one. Your doctor may also suggest nonthiazide diuretic drugs, such as spironolactone (Aldactone) or eplerenone (Inspra), which change the way your body absorbs sodium and excretes potassium by blocking the hormone aldosterone. People with resistant hypertension often have higher levels of aldosterone.

In addition, you and your doctor can review medications you're taking for other conditions. Some medications, foods or supplements can worsen high blood pressure or prevent your high blood pressure medications from working effectively. Be open and honest with your doctor about all the medications or supplements you take.

If you don't take your high blood pressure medications exactly as directed, your blood pressure can pay the price. If you skip doses because you can't afford the medication, because you have side effects or because you simply forget to take your medications, talk to your doctor about solutions. Don't alter your treatment without your doctor's guidance.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Lifestyle changes can help you control and prevent high blood pressure — even if you're taking blood pressure medication. Here's what you can do:

• Eat healthy foods. Try the Dietary Approaches to Stop Hypertension (DASH) diet, which emphasizes fruits, vegetables, whole grains and low-fat dairy foods. Get plenty of potassium, which can help prevent and control high blood pressure. Eat less saturated fat and total fat.
• Decrease the salt in your diet. Although 2,400 milligrams (mg) of sodium a day is the current limit for otherwise healthy adults, limiting sodium intake to 1,500 mg a day will have a more dramatic effect on your blood pressure. While you can reduce the amount of salt you eat by putting down the saltshaker, you should also pay attention to the amount of salt that's in the processed foods you eat, such as canned soups or frozen dinners.
• Maintain a healthy weight. If you're overweight, losing even 5 pounds (2.3 kilograms) can lower your blood pressure.
• 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. Even if you're healthy, alcohol can raise your blood pressure. If you choose to drink alcohol, do so in moderation — up to one drink a day for women and everyone over age 65, and two drinks a day for men.
• 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 and deep breathing. Getting plenty of sleep can help, too.
• Monitor your blood pressure at home. Home blood pressure monitoring can help you keep closer tabs on your blood pressure, show if medication is working, and even alert you and your doctor to potential complications. If your blood pressure is under control, you may be able to make fewer visits to your doctor if you monitor your blood pressure at home.
• Practice relaxation or slow, deep breathing. Do it on your own or try device-guided paced breathing. In some clinical trials, regular use of Resperate — an over-the-counter device approved by the Food and Drug Administration to analyze breathing patterns and help guide inhalation and exhalation — lowered blood pressure. However, some researchers question whether the devices themselves or simply taking 15 minutes to relax are responsible for lowering blood pressure.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Although diet and exercise are the best tactics to lower your blood pressure, some supplements also may help decrease it. These include:

• Alpha-linolenic acid (ALA)
• Blond psyllium
• Calcium
• Cocoa
• Cod-liver oil
• Coenzyme Q-10
• Omega-3 fatty acids
• Garlic

While it's best to incorporate these supplements in your diet as foods, you can also take supplement pills or capsules. Talk to your doctor before adding any of these supplements to your blood pressure treatment. Some supplements can interact with medications, causing harmful side effects.

You can also practice relaxation techniques, such as yoga or deep breathing to help you relax and reduce your stress level. These practices can temporarily reduce your blood pressure.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

High blood pressure isn't a problem that you can treat and then ignore. It's a condition you need to manage for the rest of your life. To keep your blood pressure under control:

• Take your medications properly. If side effects or costs pose problems, don't stop taking your medications. Ask your doctor about other options.
• Schedule regular doctor visits. It takes a team effort to treat high blood pressure successfully. Your doctor can't do it alone, and neither can you. Work with your doctor to bring your blood pressure to a safe level — and keep it there.
• Adopt healthy habits. Eat healthy foods, lose excess weight and get regular physical activity. Limit alcohol. If you smoke, quit.
• Manage stress. Say no to extra tasks, release negative thoughts, maintain good relationships, and remain patient and optimistic.

Sticking to lifestyle changes can be difficult — especially if you don't see or feel any symptoms of high blood pressure. If you need motivation, remember the risks associated with uncontrolled high blood pressure. It may help to enlist the support of your family and friends as well.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.