SN instructed patient about High blood pressure. Normal blood pressure is when your blood pressure is lower than 120 / 80 mm / Hg most of the time. High blood pressure ( hypertension ) is when your blood pressure is 140 / 90 mm / Hg or above most of the time. SN explained that the "top number" systolic indicates the pressure in the vessels when the heart beats. The "bottom number" diastolic indicates the pressure in the vessels when the heart is at rest, to between beats. This number is the most concerning number because it tells your medical team the constant pressure on these vessels. Too high (over 80) can cause damage