Hypertension, also known as high blood pressure, is a chronic medical condition characterized by elevated pressure in the arteries. It occurs when the force of blood against the artery walls is consistently too high. Blood pressure is measured using two values: systolic pressure (the pressure when the heart beats and pumps blood) and diastolic pressure (the pressure when the heart is at rest between beats). Hypertension is typically defined as having a blood pressure reading of 130/80 mmHg or higher.