Blood Pressure Category Checker Enter your blood pressure readings to see which category you fall into according to NIH and WHO standards. Systolic Pressure (Top Number in mm Hg) Diastolic Pressure (Bottom Number in mm Hg) Check My Blood Pressure Category Your Blood Pressure Category -- About Blood Pressure Categories Blood pressure is measured in millimeters of mercury (mm Hg) and recorded as two numbers: systolic (pressure when your heart beats) over diastolic (pressure when your heart rests). The categories below are based on standards from NIH and WHO to help you understand your readings. Blood Pressure Categories Normal: Less than 120/80 mm Hg Elevated: Systolic 120-129 and Diastolic less than 80 Hypertension Stage 1: Systolic 130-139 or Diastolic 80-89 Hypertension Stage 2: Systol...