What is the highest pressure against blood vessels?

The highest pressure against blood vessels is experienced during systole, which is the contraction phase of the heart. During systole, the ventricles of the heart contract and pump blood out into the arteries, causing the blood pressure to rise. The peak pressure reached during systole is known as the systolic blood pressure. In a healthy adult, systolic blood pressure typically ranges from 100 to 140 millimeters of mercury (mm Hg).