Isolated systolic hypertension: A health concern?

My doctor says my diastolic pressure is fine but my systolic pressure is too high. I thought diastolic pressure was the more important number?

- No name / No state given

Mayo Clinic hypertension specialist Sheldon Sheps, M.D., and colleagues answer select questions from readers.

Answer

For years, doctors focused primarily on diastolic blood pressure — which is the bottom number in a blood pressure reading. The theory was that the body could tolerate occasional increases in systolic blood pressure, but consistently high diastolic pressure could lead to organ damage. However, doctors now know that high systolic pressure is as important as high diastolic pressure — and even more important in people older than age 50.

If you have a diastolic number less than 90 millimeters of mercury (mm Hg) and a systolic number greater than 140 mm Hg, you have a common type of high blood pressure called isolated systolic hypertension. Isolated systolic hypertension can lead to serious health problems, such as stroke, heart disease, chronic kidney disease and dementia, and should be treated in the same way as regular high blood pressure.

The recommended goal for systolic pressure is less than 140 mm Hg. However, a concern in people with isolated systolic hypertension is that treatment may lower diastolic pressure too much, increasing the risk of a cardiovascular event. For this reason, caution is advised in treating isolated systolic hypertension in people with existing heart disease. Diastolic pressure should not be reduced to less than 70 mm Hg to attain the target systolic pressure.