Diastolic Hypertension Definition

Diastolic hypertension is a form of high blood pressure in which the pressure is abnormally high during the interval between heart muscle contractions, or heartbeats. In the two-part reading of blood pressure, usually depicted as a fraction such as 127/85, diastolic pressure is the second or lower number; the first number is systolic. Anything above 90 in that second number is considered diastolic hypertension. Some doctors consider a diastolic reading between 80 and 89 to be prehypertensive.

Significance

• Medical professionals still debate the relative significance of elevated systolic blood pressure vs. diastolic, the latter of which for years was considered the most accurate predictor of cardiovascular disease in the general population. Greater weight was put on the diastolic reading, because it generally is a more consistent number, varying less widely than systolic pressure, according to a Harvard Health Publications article on AARP.org. Diastolic pressure remains a closely watched figure in the young and adults under the age of 50.

Expert Insight

• The significance of diastolic pressure, particularly for adults over 50, was called into question by a 2003 report from the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. The committee, which is closely associated with the National Heart, Lung and Blood Institute, concluded that "in persons older than 50 years, systolic blood pressure greater than 140 mmHg--short for millimeters of mercury--is a much more important cardiovascular disease risk factor than diastolic blood pressure."

Method

• Although the debate about the relative significance of the numbers continues, the method for taking blood pressure readings remains essentially the same as it has been for decades. The instrument used is called a sphygmomanometer. It looks a bit like an oversized thermometer. To get the reading, the operator, usually a nurse, inflates a pressure cuff attached to the patient's upper arm. Listening with a stethoscope to the main artery of the arm, the cuff is inflated until blood flow is blocked. Then the cuff's pressure is released gradually to obtain first the systolic reading and then the diastolic.

Considerations

• An elevated diastolic reading from an isolated blood pressure test is insufficient evidence for a diagnosis of diastolic hypertension, according to MedlinePlus. Blood pressure fluctuates and often goes up in response to stress, nervousness or excitement. Your doctor may be concerned by a single elevated diastolic reading but will order multiple tests before confirming a diagnosis of hypertension.

Treatment

• Blood pressure numbers---both systolic and diastolic---tend to move in tandem, according to the article on AARP.org, so it is most common to see elevated readings for both measurements of blood pressure. However, there are rare cases in which one number may be out of sync with the other. Your doctor may order additional tests to find the reason for this anomaly. However, treatment for hypertension is generally with medication, although you also may be able to lower your numbers by losing weight, exercising on a regular basis and quitting smoking. Popular antihypertensive drugs include angiotensin-converting enzyme, or ACE, inhibitors, diuretics, alpha blockers, beta-blockers, calcium channel blockers, vasodilators, central alpha agonists and angiotensin receptor blockers, or ARBs.