A specific type of high blood pressure in which a person has a high systolic blood pressure but relatively normal diastolic blood pressure. Blood pressure readings, measured in millimeters of mercury (abbreviated mm Hg), are represented by two numbers, the systolic blood pressure and the diastolic blood pressure. For example, a blood pressure reading of 120/80 mm Hg represents a systolic pressure of 120 mm Hg and a diastolic pressure of 80 mm Hg. The systolic pressure is the blood pressure at the moment that the heart beats, and the diastolic pressure is the blood pressure between beats, when the heart muscle is relaxing.
A normal blood pressure for an adult is considered to be a systolic pressure less than 120 mm Hg and a diastolic pressure less than 80 mm Hg. Hypertension is defined as a systolic pressure of 140 mm Hg or higher and a diastolic pressure of 90 mm Hg or higher.
Isolated systolic hypertension is defined as a systolic blood pressure greater than or equal to 140 mm Hg with a diastolic blood pressure less than or equal to 90 mm Hg. According to guidelines issued by the National High Blood Pressure Education Program, most physicians have been taught that diastolic blood pressure is more important than systolic blood pressure, and more emphasis now needs to be placed on treating systolic hypertension.
Stroke is one of the risks of isolated systolic hypertension.