Red Blood Cell Sedimentation Rate (Erythrocyte Sedimentation Rate)
This test measures how quickly red blood cells settle in a sample of blood over time. It can help identify inflammation or infection in your body.
["ESR helps doctors check for conditions like infections, autoimmune diseases, or other inflammatory processes."]
Key facts at a glance
- LOINC
- 43402-7
- Short code
- Erythrocyte Sed Rat Bld 15M
- Synonyms
- Erythrocyte Sed Rat Bld 15M
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- m-reading
- CPT
- 85041
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order an ESR to monitor conditions such as rheumatoid arthritis, lupus, or other inflammatory diseases. It can also be used to check for infections or to evaluate how your body is responding to treatment.
How Is the Test Performed?
A small amount of your blood is drawn from a vein, typically in your arm. The blood is placed in a special tube and allowed to sit undisturbed for a set period. The rate at which red blood cells settle at the bottom of the tube is measured.
What Does the Result Mean?
The ESR result is not a specific number but a rate (often expressed in millimeters per hour). Higher rates may indicate inflammation, while lower rates may suggest no active inflammation. Your doctor will interpret the result in the context of your overall health and symptoms.
Common Conditions Monitored
ESR is commonly used to track conditions like autoimmune diseases (e.g., rheumatoid arthritis, lupus), infections, and other inflammatory disorders. It can also be part of routine check-ups for certain chronic conditions.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: ESR is a non-specific marker of inflammation. While it can suggest the presence of inflammation, it does not pinpoint the exact cause. Doctors often use it alongside other tests and clinical findings to guide diagnosis and treatment decisions.
Short name
ESR
Frequently asked questions
Why might my ESR be higher than usual?
How often should I get this test?
Can lifestyle changes affect my ESR?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy