Hypertension is also called high blood pressure. Blood pressure is the pressure inside your arteries that harmlessly pushes the blood to your body's organs and muscles so they can receive the oxygen and nutrients they need. Blood pressure is variable—it rises and falls during the day. When blood pressure stays elevated over time, it is called high blood pressure or hypertension. A blood pressure reading at or above 130 systolic or 80 diastolic (presented 130/80 mm Hg) is considered hypertensive.