What is a high blood pressure reading?

Blood pressure is measured in millimeters of mercury (mm Hg). For instance, normal blood pressure may be written 120/80 or “120 over 80.” The higher number is the systolic blood pressure. The lower number is the diastolic blood pressure.

High blood pressure (hypertension) happens when a blood pressure reading is 140/90 or higher.  Your doctor may label your high blood pressure as primary (essential) or secondary.

There is no underlying cause of primary (essential) hypertension. More than 20 percent of people with high blood pressure have secondary hypertension. This type of hypertension may be triggered by medications such as decongestants or allergy drugs, or medical conditions such as obesity or endocrine problems.

The generally accepted criteria for high blood pressure or hypertension is a reading of 140/90 or greater. A reading of 120/80 or less is considered a normal blood pressure reading. Blood pressure readings between 120/80 and 140/90 are considered pre-hypertensive and are a signal to make life-style changes.