Why Is My Diastolic Blood Pressure High?

Diastolic blood pressure is the force of the blood on the blood vessels when the heart is between beats. It is the lower of the two numbers given in a blood pressure reading. Diastolic blood pressure is considered high when it is more than 90 mmHg. A person can have high blood pressure even when his diastolic pressure is in a normal range.

Defining High Blood Pressure

• A person is diagnosed with high blood pressure when her pressure measures 140/90 or more. This means her systolic pressure--measured when the heart beats--is 140 mmHg and her diastolic pressure is 90 mmHG. Even if her diastolic pressure were lower, she would still be diagnosed with high blood pressure because her systolic pressure is high.

Causes

• For about 90 percent of the people with high blood pressure, no cause can be identified. About 5 percent of all people with high blood pressure have the condition as a side effect of another disorder such as kidney problems. A person's blood pressure can be lowered to some degree by limiting the amount of salt he eats, maintaining a healthy weight, exercising regularly, not smoking, not drinking too much alcohol and eating a healthy diet. High blood pressure tends to run in families. It affects more African-Americans than it does individuals of other groups.

Effects

• A high diastolic pressure damages the small blood vessels in the organs. They become scarred, hardened and less elastic. The risk of a blocked or ruptured blood vessel rises. People with untreated high blood pressure are more likely to have a stroke, aneurysm, heart failure, heart attack or kidney damage. High diastolic pressure is a sign that the heart is working harder than normal. A rising diastolic pressure may be a cue that a person is developing high blood pressure.

Age

• As a person grows older, her systolic pressure tends to rise while diastolic blood pressure stays the same or drops. Younger people tend to have lower systolic blood pressure and higher diastolic pressure.

Lowering Diastolic Pressure

• A blood pressure measurement reflects how hard the heart is working, how much blood is being pumped and how large and flexible the blood vessels are. If lifestyle changes don't lower blood pressure enough, a variety of drugs are available to control fluid levels in the body and lower blood pressure.