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What is blood pressure?

Dr. Deborah Raines, MSN
Nursing Specialist

Blood pressure is the force of your blood pushing against the walls of your arteries. Blood pressure is measured in millimeters of mercury (mm Hg). Blood pressure measurements consist of two numbers the systolic pressure and the diastolic pressure.

  • The top number is the systolic pressure. It shows the maximum pressure in the arteries when the heart contracts
  • The bottom number is the diastolic pressure. It shows the minimum pressure in the arteries when the heart is at rest.

Blood pressure is the pressure in the blood vessels when the heart beats, and then when the heart is resting between the beats. Blood pressure is usually defined by two numbers: the systolic number and the diastolic number. A lot of times people refer to this as either the "top number" or the "bottom number."

Blood pressure is super important. It reflects how the heart is able to circulate blood around the body to different organs. The reason we care so much is because blood pressure is implicated in so many important diseases, including heart disease and stroke, and often these are very life-altering diseases.

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Blood pressure measures the force of blood against blood vessel walls. It is measured in millimeters of mercury (mmHg) and is expressed in two numbers, such as 120/80 mmHg.

Blood pressure is the amount of force your blood exerts against the walls of your arteries. Normal blood pressure effectively and harmlessly pushes the blood from your heart to your body's organs and muscles so they can receive the oxygen and nutrients they need. Blood pressure is variable -- it rises and falls during the day. When blood pressure stays elevated over time, however, it is called high blood pressure or hypertension and needs medical attention.

Blood pressure is the force of blood against the inside walls of your arteries. If your arteries become too narrow or hard, the pressure of the blood inside goes up. This makes it harder for your heart to do its job.

Normal blood pressure is "120" over "80" (120/80) or less. If either number is higher, you might have high blood pressure. But keep in mind that blood pressure goes up and down all day long. One reading alone can't tell if you have high blood pressure. A doctor can decide if you have it.

High blood pressure can cause serious health problems. For example, high blood pressure can lead to heart attack, stroke, or kidney problems.

High blood pressure is common. It happens to all kinds of people. That's why you should try to prevent it -- and stick with treatment if you already have high blood pressure.

These days, blood pressure machines are everywhere—at the pharmacy, in your gym, in mall kiosks. Even in Wal-Mart and McDonalds. That's good. Actually, it's great. (Get your BP, hold the fries.)

That's because you need to track your blood pressure—your most crucial vital sign—even more diligently than Ebert tracks movie openings. High blood pressure still reigns as the leading cause of heart attack, stroke, heart failure, kidney failure, and impotence.

While most of your other blood numbers reveal levels of substances inside your blood, your BP gauges how your blood travels through your body. Simply, blood pressure refers to the amount of force exerted by your blood on your arterial walls as it passes through. It's measured through the systolic pressure (the pressure being exerted when the heart contracts, the top number) and the diastolic pressure (the pressure on your arteries when you heart is at rest).

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Blood pressure is the force of blood against the walls of the arteries. Blood pressure is recorded as systolic pressure over diastolic pressure. Systolic pressure is created during the contraction of the heart, while diastolic pressure is created during relaxation.

Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

To understand blood pressure, you have to understand a little bit about your heart. Your heart is basically a pump that pumps blood through your body. Blood pressure (BP) measures the force of the blood against your arteries.

There are two numbers in your blood pressure. The top number is your systolic pressure. This is the pressure in your arteries when your heart is pumping. The lower number is your diastolic pressure. This is the pressure pushing against the artery when your heart is resting between beats.

A normal blood pressure is below 120/80 mm Hg. A reading of 120/80 to 139/89 is prehypertension. You have fhypertension if your blood pressure is 140/90 or over.

Blood pressure is the force of blood exerted on the inside walls of blood vessels. Blood pressure is described in two numbers, for example "130/80," which is said as "130 over 80." The first number is the systolic pressure, or the pressure when the heart pushes blood out into the arteries. The second number is the diastolic pressure, or the pressure when the heart rests.

Dr. Bijoy K. Khandheria, MD
Cardiologist (Heart Specialist)

Blood pressure is similar to the pressure one encounters in water pipes. The upper number is systolic, the lower number diastolic. As a blood vessel loses its elasticity - often with age - the systolic blood pressure increases.

Blood pressure is the pressure of the blood against the walls of the arteries. Blood pressure results from two forces. One is created by the heart as it pumps blood into the arteries and through the circulatory system. The other is the pressure in the arteries as the heart relaxes. Blood pressure changes during the day. It is lowest as you sleep and rises when you are up and about. It can also rise when you are excited, nervous, or active.

Eric Olsen
Fitness Specialist
Blood pressure is a measure of the resistance to blood flow in the blood vessels. With each beat, the heart pumps blood throughout the body. The amount of pressure in the arteries while the heart is pumping is called the systolic blood pressure, the higher of the two numbers in a blood pressure reading. Diastolic blood pressure, the second (lower) reading, records the pressure in the arteries when the heart relaxes between beats so its chambers can refill. The higher your blood pressure, the harder your heart must work to pump blood throughout your body.
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.