ESR (Erythrocyte Sedimentation Rate)
ESR measures how quickly red blood cells settle to the bottom of a test tube in one hour. Inflammation causes red cells to clump together and settle faster. ESR has been used for over a century and remains a simple, inexpensive screening test for inflammation. It rises more slowly than CRP and falls more slowly, making it better for monitoring chronic conditions.
Reference Ranges
Male
0 – 15
mm/hr
Female
0 – 20
mm/hr
Child
0 – 10
mm/hr
Ages 1–12
Reference ranges may vary by laboratory. Always compare with the range printed on your lab report.
What Low Levels Mean
Low ESR is normal and not clinically significant. Conditions that can produce very low ESR include polycythemia, sickle cell disease, and very high white cell counts, but low ESR alone is not a concern.
What High Levels Mean
Mildly elevated ESR (20–40) can be non-specific and age-related. Moderate elevation (40–100) suggests significant inflammation — infection, autoimmune disease, or cancer. Very high ESR (>100) has a shorter list of causes: serious infection, temporal arteritis, multiple myeloma, or advanced cancer.
Frequently Asked Questions
What is the difference between ESR and CRP?
Both measure inflammation, but CRP rises and falls within hours (acute indicator), while ESR changes over days to weeks (chronic indicator). CRP is more specific for acute infections; ESR is better for monitoring chronic inflammatory diseases like rheumatoid arthritis or lupus.
Does ESR increase with age?
Yes. A commonly used formula for the upper limit of normal is: men = age ÷ 2; women = (age + 10) ÷ 2. So a 60-year-old man's upper normal is 30 mm/hr, while a 60-year-old woman's is 35 mm/hr. Mild elevation in elderly patients may not be significant.
Can ESR be high without any disease?
Yes. Obesity, anemia, pregnancy, and advancing age can all raise ESR in the absence of inflammation or disease. This is why ESR is a screening test — an elevated ESR alone is not diagnostic and always requires clinical correlation and additional testing.
This information is for educational purposes only and should not replace professional medical advice. Always consult your doctor for interpretation of your test results.
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