Blood pressure is the force that moves blood throughout the body.
Hypertension is a sustained increase in blood pressure maintained above safe limits, sometimes due to blocked or constricted blood vessels. The top number is the systolic pressure or the pressure created in the blood vessels when the heart contracts. The bottom number is the diastolic pressure or the pressure created in the blood vessels when the heart is relaxed. Blood Pressure Blood pressure changes daily. Temporary elevations may be due to exercise, anxiety or stress, fright and excitation.