What is High Blood Pressure?

Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood. High blood pressure, sometimes called hypertension, happens when this force is too high. Health care workers check blood pressure readings the same way for children, teens, and adults. They use a gauge, stethoscope or electronic sensor, and a blood pressure cuff. With this equipment, they measure:


  • Systolic Pressure: blood pressure when the heart beats while pumping blood

  • Diastolic Pressure: blood pressure when the heart is at rest between beats



Abnormal Blood Pressure


Abnormal increases in blood pressure are defined as having blood pressures higher than 120/80 mmHg. The following table outlines and defines high blood pressure severity levels.



Stages of High Blood Pressure in Adults


Systolic (top number) 


Diastolic (bottom number)


Prehypertension  120–139 OR    80–89

High blood pressure Stage 1     140–159  OR  90–99

High blood pressure Stage 2      160 or higher  OR  100 or higher


The ranges in the table are blood pressure guides for adults who do not have any short-term serious illnesses. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 mmHg.


* Source:  National Heart Lung and Blood Institute