The medical term for high blood pressure is hypertension. Blood pressure is measured by two numbers. The top number is your systolic pressure, the pressure created when your heart beats. It is considered high if consistently over 140. The bottom number is your diastolic pressure, the pressure inside blood vessels when the heart is relaxing and refilling with blood between beats. It is considered high if consistently over 90. In adults, normal blood pressure is below 120 systolic and 80 diastolic. Levels between normal and high are considered pre-hypertension.
Review Date: 1/25/2013
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Senior Physician, Massachusetts General Hospital.