# Explain why blood pressure is measured at two different values and describe what abnormally high blood pressure can indicate about a patient's health.

> AQA A-Level Physics (7408) — 3.10.3 Biological Measurement · Explain · 5 marks

> Blood pressure is measured using a sphygmomanometer and is recorded as two numbers, for example 120/80 mmHg.

## Mark scheme (5 marks)

1. The higher value is the systolic pressure / pressure when the heart contracts / pumps blood out
2. The lower value is the diastolic pressure / pressure when the heart relaxes / between heartbeats
3. Two values are needed because blood pressure changes / is not constant during the cardiac cycle
4. Abnormally high blood pressure (hypertension) puts extra strain on the heart / makes the heart work harder
5. High blood pressure increases the risk of cardiovascular disease / stroke / heart attack / damage to blood vessels / arteries

## Key terms

- [blood pressure](https://www.gradenine.co.uk/glossary/blood-pressure)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-blood-pressure-is-measured-cd91146a) · Published by Druglandscape Ltd.