Untreated high blood pressure, in particular, can damage the blood vessels, heart, kidneys, and brain. Maintaining healthy blood pressure is important, as readings outside the normal range can be problematic. The bottom number (diastolic pressure) is the force between beats. The top number (called the systolic pressure) is the force each time your heart beats. The descriptor at the end stands for “millimeters of mercury,” which blood pressure gauges used to contain. Blood pressure readings have two numbers, such as 122/79 mm Hg. Blood pressure is the force your blood exerts against the walls of arteries as your heart beats.
