JUL 31, 2017 05:33 AM PDT

Blood Pressure: What Do the Numbers Mean?

WRITTEN BY: Xuan Pham

Along with your pulse and temperature, your blood pressure is one of the most critical vital signs that reveal much about your health to your healthcare provider. Despite it being so routine now, it's still confusing to understand what blood pressure means, and to decipher what the numbers indicate about our health status.

In simple terms, blood pressure is the force that allows blood to be pumped, by the heart, through our circulatory system. Without the pressure, blood will have an exceedingly difficult time reaching all the tissues and organs. Blood pressure readings are given as two numbers: systolic over diastolic, measured in millimeters mercury (mmHg). The top number (systolic) represents the highest pressure when your heart is beating. The bottom number (diastolic) represents the lowest pressure when your heart relaxes between beats.

Normal blood pressure is typically around 120 mmHg systolic and 80 mmHg diastolic (120/80). High blood pressure (hypertension) is classified as having a systolic reading above 140 mmHg, and a diastolic reading above 80. Hypertension puts extra strain on your heart and circulatory vessels, increasing the likelihood of cardiovascular disease and stroke. Because the effects of high blood pressure can take a while to manifest, the condition is nicknamed "the silent killer."

To keep your blood pressure as low as possible, doctors recommend keeping a health body weight and and active lifestyle. Moreover, they particularly advise against high sodium foods, which cause the body to retain water and raise blood pressure.
About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
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