Inflammation . Patient guide
ESR Blood Test
What is ESR
The erythrocyte sedimentation rate (ESR) is a simple, non-specific marker of inflammation. It measures how quickly red blood cells settle in a tube: faster settling means more inflammation. It is often read alongside CRP.
This biomarker entry is being clinically reviewed by our team. The factual content draws on UK guidance (NICE, NHS, Royal Colleges and the relevant speciality society where cited).
Reference range
Reported in mm/hr. Final reports always carry the issuing laboratory's range, which is what your clinician will interpret against.
| Group | Range | Note |
|---|---|---|
| Guide (rises with age) | roughly under 15 (men) to under 20 (women) | mm/hr; age-adjusted upper limits are higher in older adults |
What it is
Inflammation raises certain blood proteins that make red cells clump and settle faster, which is what the ESR captures. Unlike CRP, which rises and falls quickly, ESR changes more slowly, so the two give complementary views of inflammation over different timescales.
Why a clinician would order it
ESR is used to investigate persistent unexplained symptoms, to help assess and monitor inflammatory and autoimmune conditions, and, importantly, in suspected polymyalgia rheumatica and giant cell arteritis, where a raised ESR supports the diagnosis.
If your level is outside the range
Symptoms of low ESR
What low can indicate. A low ESR is normal and not a concern.
Symptoms of high ESR
- Non-specific; reflects an underlying process rather than causing symptoms itself
What high can indicate. Infection, inflammation, autoimmune disease, and (with a markedly high result) conditions such as polymyalgia rheumatica, giant cell arteritis or, occasionally, an underlying malignancy. Because it is non-specific, a raised ESR is a prompt to look further, not a diagnosis in itself.
Testing tips
No fasting needed. ESR is affected by age, sex, anaemia and pregnancy, so it is interpreted with those in mind and usually alongside CRP.
Where you can get this tested
ESR is included in the following WMG Health panels. Same-day appointments at our Harley Street clinic, with results clinician-reviewed.
Want a specific combination of markers we do not have a panel for? Build a custom panel and our clinicians will design one for you.
Symptoms often investigated with ESR
ESR is commonly tested when patients present with the following symptoms. If any of these resonate with you, the linked guides explain what to look for and which test pathway is appropriate.
Sources
UK guidance our clinicians use when interpreting this marker.
This page is general patient information, not personal medical advice. A GMC-registered clinician will review your results and tailor any interpretation to you. See our Editorial Policy for how we write and review content.
Common questions about ESR
What is a normal ESR range?
Guide (rises with age): roughly under 15 (men) to under 20 (women) (mm/hr; age-adjusted upper limits are higher in older adults). Always interpret your own results against the laboratory range printed on your report, since assay-specific reference ranges vary.
What does a low ESR result mean?
A low ESR is normal and not a concern.
What does a high ESR result mean?
Infection, inflammation, autoimmune disease, and (with a markedly high result) conditions such as polymyalgia rheumatica, giant cell arteritis or, occasionally, an underlying malignancy. Because it is non-specific, a raised ESR is a prompt to look further, not a diagnosis in itself.
Do I need to fast or prepare for the ESR blood test?
No fasting needed. ESR is affected by age, sex, anaemia and pregnancy, so it is interpreted with those in mind and usually alongside CRP.
Can I order a ESR blood test privately in London?
Yes. WMG Health offers ESR as part of bespoke panels and several pre-built panels at our 134 Harley Street clinic. Results are clinician-reviewed by a GMC-registered doctor within 4 hours for the most common assays. All panels are custom-built around your specific question; bookings via /contact/ or 020 3239 3378.