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Serum/plasma mass concentration of erythrocyte sedimentation rate (ESR)

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

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

Quick summary

["ESR helps doctors track conditions like infections, autoimmune diseases, or inflammation over time."]

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

Key facts at a glance

LOINC
45320-9
Short code
EME SerPl Ql Cfm
Synonyms
EME SerPl Ql Cfm
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
confirm
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?

ESR is often used to monitor chronic conditions such as rheumatoid arthritis, lupus, or infections like tuberculosis. It may also be checked during routine health evaluations or to guide treatment decisions.

How Is ESR Performed?

A small blood sample is drawn, and the red blood cells are allowed to settle in a tube over time. The distance they descend is measured to determine ESR levels.

Why Might ESR Be Ordered?

Your doctor may order ESR if you have symptoms like fatigue, joint pain, fever, or signs of infection. It’s also used to check for hidden inflammation in conditions like cancer or kidney disease.

What Are Common Causes of Abnormal ESR?

High ESR often signals inflammation, infections, or autoimmune disorders. Low ESR may occur in rare cases of severe anemia or certain blood disorders, though this is less common.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

ESR is a simple, non-invasive test that provides a broad indicator of inflammation. While it doesn’t pinpoint the exact cause, it helps guide further testing or treatment plans when combined with clinical findings.

Short name

ESR (Serum/Plasma)

Frequently asked questions

Why do I need this test if I don’t have symptoms?
Your doctor may order ESR as part of a routine checkup, to monitor a chronic condition, or to investigate unexplained symptoms like fatigue or weight loss. It’s a quick way to assess overall health trends.
Does ESR change with age?
Yes, ESR tends to increase with age due to natural changes in blood composition. However, elevated ESR in older adults may still indicate inflammation or infection, so results should always be reviewed with your doctor.
Can diet or medications affect ESR?
Dietary factors like vitamin D deficiency or certain medications (e.g., steroids) may influence ESR, but the effect is usually mild. Your doctor will consider these factors when interpreting results.
  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