Blood pressure categories
The checker uses the adult categories from the American Heart Association. If your two numbers fall into different categories, the higher one counts.
| Category | Top number | Bottom number | |
|---|---|---|---|
| Normal | Below 120 | and | Below 80 |
| Elevated | 120 to 129 | and | Below 80 |
| High, stage 1 | 130 to 139 | or | 80 to 89 |
| High, stage 2 | 140 or higher | or | 90 or higher |
| Very high | Above 180 | and/or | Above 120 |
Why UK and US numbers differ
The NHS counts high blood pressure as 140/90 or more when measured at a clinic, or 135/85 or more when measured at home. US guidelines start “stage 1” earlier, at 130/80. Both agree that below 120/80 is ideal and that 140/90 or more needs attention. The NHS describes low blood pressure as below 90/60.
How to get a reading you can trust
- Sit quietly for five minutes first. No caffeine, exercise or smoking in the 30 minutes before.
- Sit with your back supported, feet flat on the floor and legs uncrossed.
- Rest your arm on a table so the cuff is level with your heart. Put the cuff on bare skin.
- Don’t talk while the machine is working.
- Take two readings a minute apart and note both. Measure at the same times each day for a week before drawing conclusions.
Blood pressure also shifts with the seasons. See why blood pressure rises in winter. And know the emergency signs in stroke signs: BE FAST.
Frequently asked questions
Is 130/80 high blood pressure?
In the US it’s classed as stage 1 high blood pressure. In the UK it’s below the 140/90 threshold for diagnosis, but it’s above ideal.
Which number matters more?
Both count. In people over 50 the top number is usually the stronger predictor of heart disease and stroke.
Can one high reading mean I have hypertension?
No. Stress, pain, caffeine and a full bladder can all push a reading up. Diagnosis is based on repeated readings, often at home over several days.
These tools give general estimates for adults and are not a diagnosis or a substitute for advice from a doctor. If you have symptoms or a health condition, please consult a qualified healthcare professional.