Blood pressure is the force of blood pushing against the walls of blood vessels as the heart pumps it around the body. It is measured in millimeters of mercury (mmHg) and is expressed with two numbers: systolic pressure (the higher number, indicating pressure during heartbeats) and diastolic pressure (the lower number, indicating pressure between beats). Normal blood pressure is typically around 120/80 mmHg. High blood pressure, or hypertension, can lead to serious health issues, including heart disease and stroke. Regular monitoring of blood pressure is important for maintaining overall health and preventing complications.