In brief
Measures how fast red blood cells settle in a tube of blood, a general sign of inflammation.
What it measures
How fast red blood cells settle to the bottom of a tall tube of blood.
Why it is done
To help diagnose conditions linked with inflammation, including infections, cancers and autoimmune diseases. It cannot show the cause or where the inflammation is.
Reading the results
- A high ESR suggests inflammation somewhere in the body.
- A normal ESR does not rule out active disease.
- ESR is not as accurate as CRP in most situations.
Females tend to have a slightly higher ESR.
Before the test
None.
What can affect the result
- Pregnancy
- Periods
- Ageing
- Alcohol
- Some medicines and supplements
Related topics
Sources
Test information summarised from the sources listed on this page, read on 19 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.