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Serum or plasma mass concentration of erythrocyte sedimentation rate (ESR) or erythrocyte sedimentation velocity (ESV)

Published: August 9, 2026Updated: August 16, 2026

This test measures how quickly red blood cells settle in a sample of blood, which can help identify inflammation or infection in your body.

Quick summary

["ESR helps doctors check for conditions like infections, autoimmune diseases, or other inflammatory processes."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
57494-7
Short code
11DC Pre Dex SerPl-sCnc
Synonyms
11DC Pre Dex SerPl-sCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is ESR Used For?

Doctors often use ESR to monitor conditions such as rheumatoid arthritis, lupus, or infections like pneumonia. It can also help track how well treatment is working over time.

How Is ESR Test Performed?

A small blood sample is taken from a vein, usually in your arm. The blood is placed in a special tube, and how fast the red blood cells settle is measured over time.

What Does a High ESR Mean?

A higher than expected ESR often suggests inflammation or infection. However, it can also be normal in some healthy individuals, especially older adults.

What Does a Low ESR Mean?

A lower ESR might indicate no active inflammation or infection, but it can also be influenced by factors like anemia or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

ESR/Erythrocyte Sedimentation Rate

Frequently asked questions

Why might my ESR test result be different from what I expected?
Several factors, including age, sex, and certain health conditions or medications, can affect ESR levels. Always discuss your results with your healthcare provider.
Can ESR test results change over time?
Yes, ESR can fluctuate depending on your health status, treatments, or other underlying conditions. Regular monitoring may be needed for chronic conditions.
Is ESR the same as CRP (C-reactive protein) test?
No, ESR and CRP are different tests. ESR measures red blood cell settling speed, while CRP is a protein produced by the liver in response to inflammation, often measured with a blood sample as well.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy