Blood Pressure Category Checker

Blood pressure is measured in millimeters of mercury (mmHg) with two numbers: systolic (top) and diastolic (bottom).

Blood pressure categories (American Heart Association):

Understanding the numbers:

• Systolic (top number): Pressure when your heart beats
• Diastolic (bottom number): Pressure when your heart rests between beats

What to do:

• Normal: Maintain healthy lifestyle
• Elevated: Adopt lifestyle changes (exercise, diet, reduce sodium)
• High Stage 1: Lifestyle changes + possible medication
• High Stage 2: Medication + lifestyle changes
• Crisis: Seek emergency medical care immediately

Either number is enough

Notice the “or” in the Stage 1 and Stage 2 rows. You do not need both numbers to be high. A reading of 118/92 is Stage 2 hypertension on the diastolic alone, and it is easy to miss, because the top number looks fine and most people only glance at that one. This calculator tells you which of the two put you in the category it gives.

The reverse is common in older people: systolic climbs while diastolic stays normal or even falls, as the large arteries stiffen. Isolated systolic hypertension is the usual pattern after about 60, and it carries real risk despite the reassuring bottom number.

What the 2017 change did

Before 2017 the threshold for hypertension was 140/90. The AHA and ACC moved Stage 1 down to 130/80, which reclassified a large share of the adult population overnight without anything about them changing. If you remember being told your blood pressure was fine at 135/85, that was true under the old definition and is Stage 1 under the current one. It does not automatically mean medication; it means the number is now on the record and the lifestyle conversation starts earlier.

Tips for accurate readings:

• Sit quietly for 5 minutes first, back supported, legs uncrossed
• Feet flat on the floor, arm supported at heart level. An unsupported arm can add 10 mmHg
• No smoking, caffeine or exercise for 30 minutes before
• Empty your bladder first. A full one is worth several points
• Take 2 or 3 readings a minute apart and average them, discarding the first if it is much higher
• Use the same arm each time, and mention it if the two arms differ by more than 10 mmHg

One reading is not a diagnosis. Blood pressure moves through the day, and it rises in a clinic simply because you are in one, which is common enough to have a name: white coat hypertension. A category from a single measurement means “measure properly at home over a week”, not “you have hypertension”. Home readings taken morning and evening for seven days, averaged, are what a doctor will actually want to see.