Blood Pressure 101: Why Are Those Numbers Important?

Having blood pressure is a good thing. Blood pressure helps blood circulate through your body, sending oxygen and nutrients to vital organs and keeping you alive.

What causes blood pressure?
With each beat, your heart pumps blood to your arteries and creates two kinds of force—or pressure—in your arteries.

• The first kind of force happens when blood is pumped into your arteries and through your circulatory system.
• The second force happens when your arteries resist the blood flow. In a healthy person, the arteries are elastic and they stretch a bit when blood is pumped through them. How much they stretch depends on how much force the blood exerts.

Under normal conditions, your heart beats between 60 and 80 times a minute and your blood pressure changes frequently, increasing with each heartbeat and decreasing when the heart rests between beats.

How is Blood Pressure Measured?

1. The most common blood pressure measurement tool is a cuff that is wrapped around your upper arm. A tube attaches the cuff to a reservoir of mercury at the bottom of a vertical glass tube. Using a rubber bulb, your health care practitioner blows air into the cuff, making it tight around your arm. This pressure moves the mercury in the column--up with a heart beat and down when the heart is resting between beats.
   While watching the level of mercury, the practitioner uses a stethoscope to listen to your pulse while the air is being released.
   Blood pressure measurements are shown as two numbers and measured in levels of mercury, for example: 120/80mmHg
   The first number (120) is systolic pressure, measured when the pulse is first heard.
   The second number (80) is diastolic or resting pressure, when the pulse is no longer heard and the mercury level drops.
   
2. Electronic measuring devices are becoming more common because mercury is now considered a hazardous substance. Electronic devises can eliminate some of the human error that can occur using a blood pressure cuff and a stethoscope.
   
3. With ambulatory blood pressure monitoring, you wear a device that measures your blood pressure during a 24 period. Your blood pressure readings are recorded, providing a detailed report of how your blood pressure varies during a normal day, including sleep.
   This method is useful for patients who get nervous during medical appointments, which creates a higher than normal blood pressure reading.

What Are the Ranges of Blood Pressure?

Your blood pressure changes as you go through your day. Exercise, sleep and even sitting in a chair can increase or decrease your blood pressure.
The U.S. Department of Health and Human Services offers the following guidelines for blood pressure:

• Normal blood pressure should be less than 120/85mmHg.
• Prehypertension occurs when the systolic or first number is between 120 and 139, and the diastolic or second number is between 80 and 89mmHg. People with prehypertension are twice as likely to get hypertension as people with normal blood pressure.
• Hypertension or high blood pressure occurs in people with blood pressure readings of 140/90mmHg or higher. Your health care practitioner may take several blood pressure readings over time to determine if your blood pressure is high.

Why Should I Be Concerned About High Blood Pressure?

Having untreated high blood pressure increases your risk of heart attack, stroke, heart failure, kidney disease and other life-threatening illnesses.

According to DSHS:

• People over age 55 have a 90 percent chance of developing high blood pressure.
• People who are overweight or obese increase their risk for high blood pressure.
• Treating high blood pressure can save your life. Lowering your blood pressure reduces your chance of heart attack by 27 percent, stroke by 38 percent, and heart failure by 55 percent.

See your medical provider for a blood pressure check. If it’s high, there are things you can do to reduce your blood pressure.
With proper attention, high blood pressure can be controlled, and even prevented.