high blood pressure (hypertension)
High blood pressure is a blood pressure reading of 140/90 mmHg (millimeters of mercury) or higher. Both numbers are important.
Nearly 1 in 3 American adults has high blood pressure. Once high blood pressure develops, it usually lasts a lifetime. The good news is that it can be treated and controlled.
High blood pressure is called the silent killer because it usually has no symptoms. Some people may not find out they have it until they have trouble with their heart, brain, or kidneys. When high blood pressure is not found and treated, it can cause:
What is blood pressure?
Blood is carried from the heart to all parts of the body in vessels called arteries. Blood pressure is the force of the blood pushing against the walls of the arteries. Each time the heart beats (about 60-70 times a minute at rest), it pumps out blood into the arteries. Blood pressure is at its highest when the heart beats, pumping the blood. This is called systolic pressure. When the heart is at rest, between beats, the blood pressure falls. This is the diastolic pressure.
Blood pressure is always given as these two numbers, the systolic and diastolic pressures. Both are important. Usually they are written one above or before the other, such as 120/80 mmHg (measured in millimeters of mercury, a unit for measuring pressure). When the two measurements are written down, the systolic pressure is the first or top number, and the diastolic pressure is the second or bottom number (for example, 120/80). If your blood pressure is 120/80, you say that it is "120 over 80."
Blood pressure changes during the day. It is lowest as you sleep and rises when you get up. It also can rise when you are excited, nervous, or active.
Still, for most of your waking hours, your blood pressure stays pretty much the same when you are sitting or standing still. That level should be lower than 120/80 mmHg. When the level stays high, 140/90 mmHg or higher, you have high blood pressure. With high blood pressure, the heart works harder, your arteries take a beating, and your chances of a stroke, heart attack, and kidney problems are greater.
Normal blood pressure
A blood pressure reading below 120/80 mmHg is considered normal. In general, lower is better. However, very low blood pressure can sometimes be a cause for concern and should be checked out by a doctor.
Doctors classify blood pressures under 140/90 mmHg as either normal or prehypertension.
High blood pressure
A blood pressure of 140/90 mmHg or higher is considered high blood pressure. Both numbers are important. If one or both numbers are usually high, you have high blood pressure. If you are being treated for high blood pressure and have repeated readings in the normal range, you still have high blood pressure. There are two levels of high blood pressure: stage 1 and stage 2 (see the chart below).
|Blood pressure categories
|Normal||Less than 120||Less than 80|
|High blood pressure|
|Stage 2||160 or higher||100 or higher|
* For adults 18 and older who are not on medicine for high blood pressure; are not having a short-term serious illness; and do not have other conditions, such as diabetes and kidney disease.
Note: When systolic and diastolic blood pressures fall into different categories, the higher category should be used to classify blood pressure level. For example, 160/80 mmHg would be stage 2 high blood pressure.
There is an exception to the above definition of high blood pressure. A blood pressure of 130/80 mmHg or higher is considered high blood pressure in people with diabetes and chronic kidney disease.
In many people with high blood pressure, a single specific cause is not known. This is called essential or primary high blood pressure. Research is ongoing to find the causes of essential high blood pressure.
In some people, high blood pressure is the result of another medical problem or medicine. When the cause is known, this is called secondary high blood pressure.
Who is at risk?
About 65 million American adults - nearly 1 in 3 - have high blood pressure.
In the United States, high blood pressure occurs more often in African Americans than in Caucasians. Compared to other groups, African Americans:
Many people get high blood pressure as they get older. Over half of all Americans aged 60 and older have high blood pressure. This is not a part of healthy aging! There are things you can do to help keep your blood pressure normal, such as eating a healthy diet, maintaining a healthy weight, and getting enough physical activity.
Your chances of developing high blood pressure are also higher if you:
Other things that can raise blood pressure include:
Signs and symptoms
High blood pressure is called the silent killer because you can have it for years without knowing it. The only way to find out if you have high blood pressure is to have your blood pressure measured. Using a blood pressure cuff and stethoscope or electronic sensor, your doctor or nurse can take your blood pressure and tell you if it is high.
Even though high blood pressure usually has no signs or symptoms, it is dangerous if it continues over time. It is important to find out whether you have high blood pressure and, if you do, how to keep it under control.
Only your doctor can tell you whether you have high blood pressure. Most doctors will check your blood pressure several times on different days before deciding that you have high blood pressure. A diagnosis of high blood pressure is given if repeated readings are 140/90 mmHg or higher, or 130/80 mmHg or higher if you have diabetes or chronic kidney disease.
Having your blood pressure tested is quick and easy. Your doctor or nurse will use some type of a gauge, a stethoscope (or electronic sensor), and a blood pressure cuff, also called a sphygmomanometer.
Blood pressure readings are usually taken when you are sitting or lying down and relaxed. Below are things you can do before getting your blood pressure taken:
You should ask the doctor or nurse to tell you the blood pressure reading in numbers.
You also can check your blood pressure at home with a home blood pressure measurement device, or monitor. It is important that you understand how to use the monitor properly. Your doctor, nurse, or pharmacist can help you check the monitor and teach you how to use it correctly. You also may ask for their help in choosing the right blood pressure monitor. Blood pressure monitors can be bought at discount chain stores and pharmacies. Below are additional things to do when taking your blood pressure at home:
Some people's blood pressure is high only when they visit the doctor's office. This condition is called white coat hypertension. If your doctor suspects this, you may be asked to check and record your blood pressure at home with a home monitor. Another way to check blood pressure away from the doctor's office is by using an ambulatory blood pressure monitor. This device is worn for 24 hours and can take blood pressure every 30 minutes.
Usually, the goal is to keep your blood pressure below 140/90 mmHg (130/80 mmHg if you have diabetes or chronic kidney disease). Ask your doctor what your blood pressure goal should be.
Some people can prevent or control high blood pressure by changing to healthier habits, such as:
Sometimes blood pressure stays too high even when a person makes these kinds of healthy changes. In that case, it is necessary to add medicine to help lower blood pressure. Medicines will control your blood pressure, but they cannot cure it. You will need to take blood pressure medicine for a long time.
Blood pressure medicines work in different ways to lower blood pressure. Often, two or more medicines work better than one. Some medicines lower blood pressure by removing extra fluid and salt from your body. Others affect blood pressure by slowing down the heartbeat or by relaxing and widening blood vessels.
Below are the types of medicine used to treat high blood pressure:
It is important that you take your blood pressure medicine at the same time each day and not skip days or cut pills in half to save money.
You can take steps to prevent high blood pressure. These steps include:
Living with high blood pressure
If you have high blood pressure, it is important that you:
Women and high blood pressure
In some women, blood pressure can increase if they use birth control pills, become pregnant, or take hormone therapy (HT) during menopause.
Oral contraceptives (birth control pills)
Women taking birth control pills usually have a small increase in both systolic and diastolic blood pressure. If you have high blood pressure and are using birth control pills, get your blood pressure checked regularly. Talk to your doctor about a possible rise in blood pressure and what you can do about it.
If you have high blood pressure, are age 35 or older, and also smoke, you should not take birth control pills unless you quit smoking. Women age 35 and older who smoke and use birth control pills are more likely to develop heart disease or have a stroke. High blood pressure also raises your chances of stroke and heart disease.
If you are age 35 or older, are healthy, do not smoke, and your high blood pressure is controlled, it may be safe for you to use birth control pills. Ask your doctor if birth control pills are safe for you.
Many pregnant women with high blood pressure have healthy babies. However, high blood pressure can be dangerous for both the mother and the baby. High blood pressure can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery.
If you are thinking about having a baby and you have high blood pressure, talk first to your doctor or nurse. You can take steps to control your blood pressure before and during pregnancy. Regular prenatal care (health care during pregnancy) is very important for your and your baby's health.
Before becoming pregnant:
While you are pregnant:
Some women develop high blood pressure for the first time in the middle of their pregnancy. In the most serious cases, the mother develops a condition called preeclampsia or "toxemia of pregnancy." This condition can threaten the lives of both the mother and the unborn child.
Even though high blood pressure during pregnancy can be serious, most women with high blood pressure and those who develop preeclampsia have successful pregnancies. Getting early and regular prenatal care is the most important thing you can do for you and your baby.
Postmenopausal hormone therapy
Large randomized trials indicate that postmenopausal hormone therapy causes a small increase in systolic blood pressure. If you start taking postmenopausal hormone therapy, you should have your blood pressure checked regularly. Your doctor can help answer your questions.
Older adults and high blood pressure
A common form of high blood pressure in older adults is isolated systolic hypertension (ISH).
ISH is high blood pressure, but only the top (systolic) number is high (140 or higher). ISH can be as harmful as high blood pressure in which both numbers are high.
ISH is the most common form of high blood pressure for older adults. About 2 out of 3 people over age 60 with high blood pressure have ISH.
You may have ISH and feel fine. As with other types of high blood pressure, ISH often causes no symptoms. To find out if you have ISH - or any type of high blood pressure - get your blood pressure checked.
If not treated, ISH can cause damage to your arteries and to body organs. ISH is treated the same way as high blood pressure in which both systolic and diastolic pressures are high - by making changes in your health habits and with blood pressure medicines.