Blood Pressure Numbers: What the Two Numbers Mean
A blood pressure reading has two numbers. This page explains, in plain words, what each number means and which group a reading falls into.
What the two numbers mean
A reading is written like this, with the top number first:
The pressure in your arteries when your heart beats and pushes blood out.
The pressure in your arteries when your heart rests between beats.
In the example above, 120 is the top (systolic) number and 80 is the bottom (diastolic) number.
The five groups for adults
The American Heart Association puts adult readings into five groups. A reading takes the highest group that either number reaches — so if one number is in a higher group, the whole reading is in that higher group.
-
Normal
Top number below 120 AND bottom number below 80.
-
Elevated
Top number 120–129 AND bottom number below 80.
-
High blood pressure — Stage 1
Top number 130–139 OR bottom number 80–89.
-
High blood pressure — Stage 2
Top number 140 or higher OR bottom number 90 or higher.
-
Hypertensive crisis
Top number higher than 180 and/or bottom number higher than 120. See the red box below — this one needs help right away.
Crisis range: act right away
If a reading is in the crisis range — top number higher than 180 and/or bottom number higher than 120 — the American Heart Association says to consult a doctor immediately.
Call 911 right away if there is also:
- Chest pain
- Shortness of breath
- Back pain
- Numbness
- Weakness
- Change in vision
- Difficulty speaking
Find the group for one reading
Type in the two numbers from a single reading. The finder shows which American Heart Association group that reading falls into.
One reading is not a diagnosis. Clinicians diagnose high blood pressure from repeated readings over time. Home cuffs can also read wrong if the cuff size or position is off.
How to take a reading the way the AHA recommends
Small things can push a reading up or down. The American Heart Association recommends these steps:
- Empty your bladder first.
- Sit with your back supported and your feet flat on the floor.
- Rest quietly for 5 minutes before the reading.
- No smoking, caffeine, or exercise in the 30 minutes before.
- Support your arm so the cuff is at heart level.
- Use the right cuff size, on bare skin.
- Don't talk during the reading.
When to talk to a doctor
Talk to a doctor or pharmacist if:
- Your readings are repeatedly in the Stage 1 or Stage 2 range.
- You get any reading in the crisis range.
- Any reading worries you, for any reason.
Sources
- American Heart Association — blood pressure categories and measurement.
- MedlinePlus — blood pressure.
- CDC — high blood pressure facts.
Facts checked November 2026.