ESR (sedimentation rate): what this inflammation marker tells you

ESR stands for erythrocyte sedimentation rate, and it measures something surprisingly simple: how fast your red blood cells settle to the bottom of a thin tube in one hour. It sounds old-fashioned, and it almost is, because the test is more than a century old. Still, ESR remains useful as a broad clue for inflammation (Harrison 2015). In our experience people understand their ESR better once they know what happens in that tube.

This article expands on the overview about inflammation markers in your blood, focusing on ESR.

What does ESR measure?

During inflammation certain blood proteins change, including fibrinogen. Those proteins make your red cells stick together into heavier clumps, which settle faster. So a high ESR points indirectly to inflammation. The word indirectly matters: ESR measures the effect, not the inflammation itself, which makes it broad but less specific than CRP.

Why does ESR react slowly?

The proteins that drive ESR build up and break down more slowly than CRP. So ESR rises only after a day or longer, and stays raised longer while the inflammation is already healing. That slow character can be useful for processes that have run for weeks, where a fast test may already read normal.

What affects your ESR?

Because of these influences, a slightly raised ESR is rarely alarming on its own. It gains meaning together with your symptoms and sometimes a repeat measurement.

What does a raised ESR mean?

A raised ESR means there is inflammation somewhere, or a change in your blood proteins. The causes range widely, from a simple infection to something that needs longer attention. The value points a direction but does not name the problem.

Imagine your GP draws blood because you have been tired for weeks with stiff joints in the morning. The ESR is raised, the CRP normal. That pattern can fit a slower-running process, and is a reason to look further together rather than conclude straight away.

How to have your ESR tested?

ESR comes from a regular blood draw and is often part of a broader panel. At Vitalcheck you can measure your markers without a referral in the basic health checkup. You can read up on ESR and its fast counterpart CRP. If your ESR is raised, discuss it with your GP before drawing conclusions.

References

• Harrison M. Erythrocyte sedimentation rate and C-reactive protein. Aust Prescr. 2015. PMID: 26648629.
• Sproston NR, Ashworth JJ. Role of C-Reactive Protein at Sites of Inflammation and Infection. Front Immunol. 2018. PMID: 29706967.
• Thuisarts.nl. About blood testing.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.