Everyday Health

Everything You Need to Know About Blood Pressure

Originally published March 21, 2017

Last updated April 26, 2024

Reading Time: 3 minutes

What does it mean to have a high or low blood pressure? How does your blood pressure impact your overall health?

Normal blood pressure is a vital body function. Without blood pressure — the force that moves blood through our circulatory system — oxygen or nutrients would not reach our tissues and organs through our arteries nor would white blood cells be distributed through our bodies. Blood pressure also helps carry the toxic waste in our bodies through our liver and kidney.

The heart creates blood pressure by pushing out blood when it contracts with each heartbeat. Blood pressure is also caused by the difference in pressure between the heart and the smaller branches of the arteries. The condition of the arteries also affects the blood pressure and flow.

How is blood pressure measured?

Blood pressure is expressed with two equally important numbers, for example, 120/80. The top number represents systolic pressure, the amount of pressure in arteries during the contraction of the heart muscle. The bottom number is the diastolic pressure, which refers to the blood pressure when the heart muscle is between beats.

What is a normal blood pressure reading?

When the blood pressure is normal, the top number is less than 120, and the bottom number is less than 80, according to the American Heart Association (AHA).

“In order to get an accurate reading, patients should use an automated oscillometric device that measures blood pressure in the brachial artery (upper arm) and perform measurements in a quiet room after five minutes of rest in the seated position with the back and arm supported,” says Rose Taroyan, MD,  a family medicine physician at Keck Medicine of USC and clinical associate professor of family medicine at the Keck School of Medicine of USC. “At least 12 or 14 measurements should be obtained, with both morning and evening measurements taken, over a period of one week.”

Understanding high or low numbers

If the numbers are higher than the ideal range, the heart is working too hard to pump blood to the body. When the numbers are lower than ideal it means that your blood pressure is too low and doesn’t supply your body and heart with enough oxygenated blood. Low blood pressure is known as hypotension. It’s not normally a cause for concern unless you start to experience symptoms.

How to keep a healthy blood pressure level

If your blood pressure is in the normal range, you won’t need any medical intervention; however, you should maintain a healthy lifestyle and a healthy weight to prevent hypertension from developing. You may need to be even more cautious about your lifestyle if hypertension runs in your family.

The following recommendations can help you maintain healthy blood pressure:

  • Keep a healthy body weight.
  • Stick with a regular diet of fruits, vegetables and low-fat dairy products.
  • Cut down on sodium intake.
  • Regular aerobic exercise, such as brisk walking, running or swimming, for at least half 90 to 150 minutes per week.
  • Keep alcohol intake to no more than one to two drinks a day for men and one drink a day for women.


Ramin Zahed
Ramin Zahed is a Los Angeles-based author and journalist.