Understanding Diastolic Blood Pressure: What's Normal?

Blood pressure is written as a combination of two numbers, for example 120/80. The normal range for blood pressure is when the systolic number (written first) is less than 120 and the diastolic number (written second) is less than 80.

Blood pressure

• The American Heart Association defines blood pressure as the pressure of the blood against the walls of the arteries.

Systolic Pressure

• Systolic pressure is the measurement of the blood's force against the arteries as the heart pumps.

Diastolic Pressure

• Diastolic pressure is the force against the arteries between beats while the heart is at rest.

High Blood Pressure (hypertension)

• An individual is considered to have mild high blood pressure if her systolic number remains between 140 and 159 and her diastolic number remains between 90 and 99. A systolic number continuously running greater than 160 and a diastolic number greater than 100 is indicative of moderate to severe high blood pressure.

Low Blood Pressure (hypotension)

• A systolic number continuously running less than 90 and a diastolic number less than 60 is indicative of low blood pressure.

Conditions That Affect Blood Pressure

• There are a number of conditions that can cause blood pressure to fluctuate. Some examples are heart disorders, neurological disorders, kidney and urological problems, medications, infection and stress.