Blood pressure categories: what the numbers mean

A blood pressure reading has two numbers: systolic (the top, pressure when the heart beats) and diastolic (the bottom, pressure between beats). Both are measured in mm Hg.

The ACC/AHA categories

• Normal: below 120 and below 80
• Elevated: 120-129 and below 80
• High blood pressure, stage 1: 130-139 or 80-89
• High blood pressure, stage 2: 140 or higher, or 90 or higher
• Hypertensive crisis: 180 or higher and/or 120 or higher — contact your clinician immediately, or call emergency services if you also have symptoms

If the two numbers fall in different categories, the reading counts as the higher one.

One reading is not a diagnosis

A single high reading does not mean you have hypertension, and a single normal one does not rule it out. Clinicians diagnose from patterns — several readings, on different days, taken correctly. That is exactly why home records are useful.

Your target may be different

Treatment targets are personal. Age, diabetes, kidney disease, heart disease, and the medicines you take all affect the number your clinician aims for. Ask at your next visit: “What should my blood pressure be, and when should I call you?”