An Introduction to High Blood Pressure
Blood pressure is a measure of the pressure inside your blood vessels -- both while the heart is beating and while it is relaxed. High blood pressure, as you might guess, is when the pressure within your blood vessels is too high. This is also known as
hypertension.
About 65 million American adults -- nearly 1 in 3 -- have high blood pressure.
Why Is Blood Pressure Important?
Blood pressure is the amount of force (pressure) that blood exerts on the walls of the vessels as it passes through them. As blood is pumped from your heart into your blood vessels, enough pressure is created to send it to all other parts of your body. As vessels travel away from the heart, they branch off and gradually get smaller, just like the branches of a tree. One branch may go to the brain, while another may go to your kidneys. Blood pressure keeps the blood flowing through all these branches so that your body's cells get the oxygen and nutrients they need and waste matter can be removed.
Causes of High Blood Pressure
In most people, the specific cause or
causes of high blood pressure are not known. This is called primary or essential hypertension. In other people, the condition is the result of another medical problem or medication. When the cause is known, this is called secondary high blood pressure or secondary hypertension.
If a person is diagnosed with high blood pressure, it doesn't mean that he or she is "too nervous," overanxious, or obsessive. This is a popular myth. High blood pressure is not nervous tension. In fact, many people who are perfectly calm have the condition.
Risk Factors for High Blood Pressure
While for most people there is no known cause of high
blood pressure, there are factors that can increase a person's chance of developing it. Some of these risk factors cannot be controlled, including:
- Being African American
- Being a male over the age of 45 or a female over the age of 55
- Having a family history of the condition.
However, some risk factors can be controlled, including:
- Being overweight or obese
- Being physically inactive
- High salt (sodium) intake
- Low potassium intake (due to not eating enough fruits and vegetables)
- Excessive alcohol consumption
- Having diabetes
- Having prehypertension (that is, blood pressure in the 120-139/80-89 mmHg range).
Symptoms of High Blood Pressure
Most people with high blood pressure don't have any symptoms. This is because the condition doesn't cause problems over a day or weeks, or even months. It usually takes several years for high blood pressure to cause noticeable symptoms, and even when it does cause problems, the symptoms are often mild and nonspecific (meaning they could be caused by several different conditions). For this reason, high blood pressure is often referred to as "the silent killer." People with the condition typically don't even realize they have it until they have
blood pressure readings that are too high.
Testing for High Blood Pressure
Having a
blood pressure test is quick and painless. It involves using either a
sphygmomanometer or blood pressure machine to measure the blood pressure. Blood pressure is measured in millimeters of mercury (mmHg) and recorded as two numbers: systolic pressure "over" diastolic pressure. For example, the doctor or nurse might say "130 over 80" as a
blood pressure reading. This is written as 130/80. Many people define
normal blood pressure as an average reading of 120/80 or below.
Both numbers in a blood pressure reading are important. As we grow older,
systolic blood pressure is especially important.
Diagnosing High Blood Pressure
High
blood pressure can only be diagnosed after taking several readings to find your
average blood pressure. To determine your average blood pressure, your blood pressure needs to be taken two or more times, and each reading must be from a different day. If the average of these readings is more than 140/90, you have high blood pressure.
A single reading that is more than 140/90 doesn't necessarily mean that you have high blood pressure; however, your healthcare provider will probably want to monitor your blood pressure over time to see if it stays there. You can also have high blood pressure if the average of only one of the numbers (systolic or diastolic) is too high.
Effects of High Blood Pressure
The body structures that chronic (long-term) high blood pressure affects most include the:
- Blood vessels
- Heart
- Brain
- Kidneys
- Eyes.
Treating High Blood Pressure
Lifestyle changes are the first form of
high blood pressure treatment. They usually help improve a person's quality of life as well. It may take three to six months before your healthcare provider sees the full benefit of lifestyle changes in your condition. Some of these changes may include:
Types of High Blood Pressure
There are a number of different categories of high
blood pressure. Most people have what is known as essential
hypertension or primary hypertension. This is high blood pressure where the cause is not known. Other types include:
- Preeclampsia (also known as pregnancy-induced hypertension, toxemia of pregnancy, or acute hypertensive disease of pregnancy)
- Eclampsia
- Chronic hypertension
- Chronic hypertension with preeclampsia
- Late hypertension (also called gestational hypertension).
High Blood Pressure: Looking Ahead
Many people do not have
symptoms of high blood pressure or discomfort, so they find it easy to ignore their condition. However, this significantly increases the chances of having:
Getting the condition under control may add years to a person's life. Healthy lifestyle changes often improve both a person's high blood pressure and his or her quality of life.