High blood pressure is a common disease in which blood flows through blood vessels (arteries) at higher than normal pressures.

Measuring Blood Pressure

Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood. High blood pressure, sometimes called hypertension, happens when this force is too high. Health care workers check blood pressure readings the same way for children, teens, and adults. They use a gauge, stethoscope or electronic sensor, and a blood pressure cuff. With this equipment, they measure:

• Systolic Pressure: blood pressure when the heart beats while pumping blood
• Diastolic Pressure: blood pressure when the heart is at rest between beats

Health care workers write blood pressure numbers with the systolic number above the diastolic number. For example:

Normal Blood Pressure

Normal blood pressure for adults is defined as a systolic pressure below 120 mmHg and a diastolic pressure below 80 mmHg. It is normal for blood pressures to change when you sleep, wake up, or are excited or nervous. When you are active, it is normal for your blood pressure to increase. However, once the activity stops, your blood pressure returns to your normal baseline range.

Blood pressure normally rises with age and body size. Newborn babies often have very low blood pressure numbers that are considered normal for babies, while older teens have numbers similar to adults.

Abnormal Blood Pressure

Abnormal increases in blood pressure are defined as having blood pressures higher than 120/80 mmHg. The following table outlines and defines high blood pressure severity levels.

Stages of High Blood Pressure in Adults

The ranges in the table are blood pressure guides for adults who do not have any short-term serious illnesses. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 mmHg.

Although blood pressure increases seen in prehypertension are less than those used to diagnose high blood pressure, prehypertension can progress to high blood pressure and should be taken seriously. Over time, consistently high blood pressure weakens and damages your blood vessels, which can lead to complications.

Types of High Blood Pressure

There are two main types of high blood pressure: primary and secondary high blood pressure.

Primary High Blood Pressure

Primary, or essential, high blood pressure is the most common type of high blood pressure. This type of high blood pressure tends to develop over years as a person ages.

Secondary High Blood Pressure

Secondary high blood pressure is caused by another medical condition or use of certain medicines. This type usually resolves after the cause is treated or removed.

Key Points

• High blood pressure is a serious condition that can lead to coronary artery disease (CAD), heart failure, stroke, kidney failure, and other health problems.
• High blood pressure itself usually has no symptoms. You can have it for years without knowing it. Rarely, headaches may occur. Some people only learn that they have high blood pressure after it causes health problems, such as coronary heart disease, stroke, or kidney failure.
• All blood pressure levels above 120/80 mmHg increase your risk for the health problems related to hypertension. A blood pressure level of 140/90 mmHg or higher is considered too high for most adults. If you have diabetes or chronic kidney disease, a blood pressure of 130/80 mmHg or higher is considered high blood pressure.
• Knowing your blood pressure numbers is important, even when you're feeling fine.
• When high blood pressure has no known cause, it may be called "essential hypertension", "primary hypertension", or "idiopathic hypertension". When another condition causes high blood pressure, it's sometimes called secondary high blood pressure or secondary hypertension.
• Blood pressure tends to rise with age. Certain medical problems and medicines may cause blood pressure to rise. In some women, blood pressure can go up if they use birth control pills, become pregnant, or take hormone replacement therapy.
• High blood pressure is treated with lifestyle changes and medicines. Lifestyle changes include following a healthy eating plan, doing enough physical activity, maintaining a healthy weight, quitting smoking, and managing and coping with stress.
• If you have normal blood pressure, you can take steps to prevent or delay high blood pressure. Healthy lifestyle habits can help you maintain normal blood pressure.
• If you have high blood pressure, you can take steps to prevent the long-term problems it can cause. Adopt healthy lifestyle habits and follow the treatment plan your doctor prescribes.

Reference: The National Heart, Blood, and Lung Institute.

Last updated March 7, 2017