I know, I know. We've talked about this before, but the basics are worth repeating.
Blood pressure is the pressure that occurs in the blood vessels when the blood is driven from the heart to the rest of the body. The peak in pressure is the so-called systolic or upper pressure, whereas the lower or diastolic pressure is the opposite - the lowest measurement.
The systolic pressure is the one that best predicts the risk of complications. This is especially true if you are over fifty years old. One reason is that the excess pressure rises more with age, because the older you get, the stiffer the blood vessel walls in the artery become.
The rise in systolic pressure reflects not only the degree of stiffness, but also atherosclerosis.
Isolated high systolic pressure means a greater risk than when both pressures are high. Isolated systolic blood pressure increase means that the upper pressure is higher than 140 mmHg while the lower is as it should be, ie below 90 mmHg. It is the most common type of high blood pressure in the elderly and you should get the same treatment for what when both pressures are elevated.