Understanding Diastolic Blood Pressure: What It Means & Normal Ranges

Blood pressure is the force of blood pushing against the artery walls. Blood pressure is always measured with two numbers: systolic, when the heart is pumping blood, and diastolic, when the heart rests between beats. The diastolic reading is the second number written in the calculation and is the lower of the two.

Function

• As blood vessels leave the heart, they branch off and gradually become smaller. Diastolic blood pressure keeps blood moving through these vessels, so cells obtain oxygen and nutrients, and waste matter is removed.

Identification

• High blood pressure occurs when the force of blood pushes against the artery walls more strongly than it should. It is diagnosed when the readings are higher than normal on two different days.

Normal Blood Pressure

• The normal range for diastolic pressure is between 60 to 89. Having two readings in the 80 to 89 range, however, results in a diagnosis of prehypertension, usually modifiable through diet and lifestyle changes.

High Blood Pressure

• Chronic high diastolic blood pressure can cause artery damage, stroke, heart attack and kidney failure. Readings over 110 may prompt a physician to administer immediate medication and advise close monitoring.

Low Blood Pressure

• Low diastolic pressure is below 60. Chronic low diastolic pressure inhibits the blood's ability to carry oxygen and nutrients to all the cells, and to remove waste matter. This can cause cell damage. Short-term low blood pressure can cause dizziness and fainting.

Blood Pressure Variations

• Diastolic blood pressure, like systolic, changes throughout each day. Diastolic pressure can change because of exercise, tension, posture and nicotine use.