High blood pressure is a condition that increases your risk of heart disease, stroke, heart failure, kidney disease, and other health problems. Blood pressure is the force your blood applies to the walls of your arteries as it circulates throughout your body. High blood pressure occurs when this force is raised above normal levels. High blood pressure is also called hypertension.
While it’s normal for blood pressure to change—rise and fall—throughout the day, sustained high blood pressure puts you at greater risk for serious health conditions.
The Centers for Disease Control and Prevention (CDC) estimates that about one in three (or about 31 percent) of adults in the United States has high blood pressure. The CDC also estimates that 25 percent of U.S. adults have prehypertension, or higher than normal blood pressure, a condition that puts you at greater risk for high blood pressure.
High blood pressure can result in hardening of the arteries, which decreases the flow of blood and oxygen to the heart. When the heart isn’t receiving enough blood or oxygen, you’re at risk for chest pain (angina), heart failure, or heart attack. High blood pressure is also a risk factor for kidney disease, aneurysms, and bursting or bleeding of blood vessels in the eyes, which can lead to vision changes or blindness.
Understanding Blood Pressure: What the Numbers Mean
When you have your blood pressure measured, the reading will include two numbers: the first is called systolic, and the second is call diastolic. Systolic pressure is the pressure in your blood vessels when your heart beats; diastolic pressure is the pressure in your blood vessels when your heart rests between beats. The units used to measure blood pressure are millimeters of mercury, or mmHg. An example of a blood pressure reading is “120 over 80,” which can be written as “120/80 mmHg.”
Levels of blood pressure are as follows:
Blood pressure tends to rise with age (but, as you’ll learn later in Prevention, there are steps you can take to prevent a rise or control levels). As well, certain medical problems may contribute to high blood pressure; these include chronic kidney disease, thyroid disease, and sleep apnea. High blood pressure is also common among people with diabetes. As well, some medicines can raise blood pressure; these include asthma medicines, cold medicines, and for some women, birth control pills or hormone therapy. It’s also possible that a woman’s blood pressure may rise during pregnancy.
People with high blood pressure rarely have symptoms. It can only be detected when a healthcare professional measures your blood pressure.
A blood pressure test, which is performed by your doctor or nurse, is used to diagnose high blood pressure. Your doctor or nurse will check your blood pressure on several occasions to make sure that the reading is correct.
A diagnosis of high blood pressure is made with a blood pressure level of 140/90 mmHg or higher over time. For people with diabetes or kidney disease, 130/80 mmHg indicates high blood pressure.
A blood pressure test is simple and painless. Your doctor or nurse will use a gauge, a stethoscope or electronic sensor, and a blood pressure cuff, which is placed around your arm. Before the test, do the following to avoid a short-term raise in blood pressure and ensure an accurate reading: don’t drink coffee or smoke, go to the bathroom before the test, and sit still for five minutes before the test.
Several conditions, behaviors, and personal characteristics may raise your risk of developing high blood pressure. These include:
Treatment for high blood pressure involves both medicines and lifestyle changes. Once you’ve been diagnosed with high blood pressure and begin treatment, you’ll likely have to continue treatment for the rest of your life. Staying on treatment will help you avoid the health risks associated with high blood pressure and maintain a full, active life. The goal of treatment is generally to get blood pressure below 140/90 mmHg and maintain that level. For people with diabetes or kidney disease, target blood pressure is 130/80 mmHg.
Several types of medicines are used to lower high blood pressure. They each work in different ways and are often combined. Medicines used to lower blood pressure include:
The lifestyle changes that can help you control high blood pressure can also help you prevent the condition. They include maintaining a healthy diet and a healthy weight, getting enough physical activity, not smoking, and managing stress. For more details about these healthy habits, see Prevention below.
Fortunately, there are lifestyle choices you can make to keep your blood pressure at normal levels and thereby reduce your risk of health conditions associated with high blood pressure like heart disease and stroke. If you have high blood pressure, making these choices may help you lower it. Here are some of the things you can do:
High Blood Pressure. The Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/bloodpressure/. (Accessed October 2010).
High Blood Pressure. The National Heart Lung and Blood Institute website. Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/Hbp/HBP_All.html. (Accessed October 2010).