THE BASICS: “What is blood pressure?”
Blood pressure (BP) is the force (pressure) your blood exerts on the inner walls of your arteries as it flows through them.
Blood pressure is a measure of:
- How much blood your heart pumps
- How resistant to blood flow your arteries are
Blood pressure increases as arteries narrow, making the heart pump harder.
When the pressure of your blood against your artery walls becomes high enough to start damaging your health, you have high blood pressure:
- A leading cause of heart attacks and strokes
High blood pressure is very common:
- More than 30 percent of adult Americans have it—about 68 million, almost one in three.
- Nearly 60 million Americans over age 55 have a 90 percent probability of developing it.
High blood pressure cannot be cured. Once you have high BP, you can expect to have it for the rest of your life.
Fortunately, it can be treated and stabilized within a normal range. Along with medication, if needed, this will require your day-by-day commitment to:
- Maintaining a healthy weight
- Exercising regularly
- Following a healthy eating plan
- Reducing salt and sodium intake
- Drinking alcoholic beverages in moderation if at all
That may sound like a lot! But it’s really no more than what many healthy people do who don’t have high blood pressure.
- And if you do it, along with taking your blood pressure medication (if needed), checking your BP, and seeing your doctor regularly for a blood pressure test, you have a good chance of being healthy, too.
Many people have high blood pressure for years before it’s diagnosed.
- This is because it typically causes no symptoms, even when it’s dangerously high.
- High blood pressure is often called “the silent killer.”
The test used to check for high blood pressure gives a result using two numbers, written one atop the other the way you would write a fraction, that measure millimeters of mercury (mmHg). Thus:
- A healthy BP is 140/90 mmHg (spoken of as “140 over 90”) or lower.
The top number indicates the systolic pressure (pressure during a heartbeat), and the bottom number indicates the diastolic pressure (pressure when the heart relaxes between beats).
Today, abnormal blood pressure is classified as follows:
- 120/80 to 139/89 mmHg: Prehypertension (“almost” high blood pressure)
- Prehypertension tends to progress over time.
- Doctors watch people in this range closely to detect progression to higher BP.
- 140/90 mmHg to 160/100: Stage 1 hypertension
- Stage 1 may or may not be treated with medication, depending on the person’s risk factors and lifestyle.
- Above 160/90: Stage 2 hypertension
- Stage 2 is seriously high blood pressure requiring immediate medical treatment.
Seek medical help immediately if you have these signs of what doctors call malignant high blood pressure (it’s not related to cancer) or hypertensive crisis:
- Blood pressure much higher than normal—for example, 180/110 or higher
- Severe headache, particularly if it’s pulsating behind your eyes
- Nausea and/or vomiting
- Blurred vision
Call your doctor if:
- You have two or three high blood pressure readings in a row
- This may mean your treatment isn’t working and/or another disorder, such as kidney disease, is causing your high blood pressure.
- Your BP rises above the normal range at least twice even though it’s typically normal and under control.
- You think you’re experiencing side effects from your blood pressure medication.
In as many as 95 percent of people with high blood pressure no cause can be identified.
- This is called essential, or primary, hypertension.
Some people develop high BP due to condition-related causes (secondary hypertension), which include kidney problems, adrenal gland tumors, congenital (present at birth) blood vessel defects, and pregnancy.
Over-the-counter (OTC) and prescription medications, including pain relievers, cold remedies, and appetite suppressants, can also raise your BP.
Risk factors for high blood pressure include:
- Gender: High blood pressure affects more men than women.
- Age: The older you are, the higher your risk.
- Race: High blood pressure, and serious complications from it, are more common in African-Americans.
- Family history: High blood pressure can run in families.
- Overweight/obesity: Extra flesh creates the need for extra blood flow, increasing artery-wall pressure.
- Inactivity: Besides being a factor in weight gain, inactivity tends to make your heart work harder and increase artery-wall pressure.
- Smoking or chewing tobacco: Either raises blood pressure at the time, and both contain chemicals that can damage and narrow artery walls.
- Secondhand smoke can also increase blood pressure.
- Excessive alcohol intake: Years of heavy drinking can damage your heart.
- High stress levels: Even a temporary bout of high stress can cause a sharp rise in BP.
- Smoking, drinking, or overeating in response to stress can make the BP problem worse.
- Excess salt: Too much sodium can increase blood pressure by causing the body to retain fluids.
- Potassium deficiency: This can cause your sodium level to rise.
- Vitamin D deficiency: Although not yet proven, this may affect a kidney enzyme involved in blood pressure regulation.
- Certain chronic diseases and disorders, including:
- Kidney disease
- High cholesterol
Untreated, high blood pressure can cause serious complications, including:
- Atherosclerosis (artery hardening and thickening), which can cause a heart attack or stroke
- Aneurysm (blood vessel weakening and bulging), which can rupture and become life-threatening
- Heart failure, which can result from insufficient blood flow due to blood vessel narrowing, forcing the heart to work harder and harder over time
- Kidney damage, which can weaken and narrow blood vessels so the kidneys no longer work normally
- Damage to blood vessels in the eyes, which can lead to vision loss
- Problems remembering and/or understanding, which are more common in people with high blood pressure
- Diabetes, heart attack, or stroke related to “metabolic syndrome,” a cluster of risk factors, including high blood pressure, related to your body’s metabolism (if you have high BP, the more of these metabolic-syndrome risk factors you have, the higher your risk):
- Increased waist circumference
- Low high-density lipoprotein (HDL, “good”) cholesterol levels
- High triglyceride and/or insulin levels
Now that you’ve learned more about the “silent killer,” you’re better prepared to seek the care you may need if you have high blood pressure. Next step:
- Getting to know the health professionals who can help