ESR
An older, slower marker of inflammation whose normal range rises with age.
What it means
A measure of how fast red blood cells settle in a tube — which happens faster when inflammatory proteins are present.
It moves much more slowly than CRP, taking days to rise and weeks to fall, which makes it better for tracking long-running conditions and worse for detecting something acute.
The normal range rises with age, and is higher in women. An ESR of 30 in an 80-year-old woman may be entirely unremarkable; the same figure at 25 would not be.
In practice
Often requested alongside CRP, particularly where an inflammatory or autoimmune condition is being considered.
It is central to diagnosing polymyalgia rheumatica and giant cell arteritis, where a markedly raised ESR alongside the right symptoms carries real weight.
Why it matters
Check the result has been interpreted for your age, since a great deal of unnecessary worry comes from applying a young person's range to an older one.
If it is raised alongside new headache, scalp tenderness or jaw pain on chewing in someone over 50, that is urgent — giant cell arteritis threatens sight and needs same-day assessment.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026