Erythrocyte Sedimentation Rate
The erythrocyte sedimentation rate, or ESR, measures how quickly your red blood cells settle to the bottom of a thin tube over one hour. Faster settling tends to reflect more inflammation in the body.
Westergren method; upper limit rises ~5 mm/h per decade after age 50
ESR is a simple, long-standing marker of inflammation, though it is non-specific and doesn't point to any single cause. It is often used to help detect or monitor inflammatory conditions over time. Because many everyday factors can influence it, it is interpreted as one clue among many.
A raised ESR suggests inflammation somewhere in the body, but it cannot tell you where or why on its own. It can rise with infections, inflammatory conditions, and simply with older age or pregnancy, so context is essential. Your clinician will interpret it together with your symptoms and other tests.
A low ESR is generally not a concern and is often a normal finding.
Normal ranges vary with age and sex and differ by lab, so use your report's range and discuss any elevation with your clinician.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.