Sedimentation Rate: Definition, ESR Test, and Results
Quick summary: The sedimentation rate, also called ESR, is a blood test that shows how fast red blood cells settle in a tube. It is used as a general marker of inflammation, but it...
This content is for educational purposes only and does not replace medical advice, diagnosis or treatment from a qualified healthcare professional.
Quick summary: The sedimentation rate, also called ESR, is a blood test that shows how fast red blood cells settle in a tube. It is used as a general marker of inflammation, but it does not diagnose a specific condition on its own.
Results are interpreted together with symptoms, medical history, and other tests.
Medical disclaimer: This article is for general information only. It does not replace advice from a doctor, nurse, or pharmacist. Test results should always be reviewed in context with your overall health and the official laboratory reference range.
What is the sedimentation rate?
The sedimentation rate is a laboratory measure of how quickly red blood cells settle to the bottom of a tube of blood. It is often used as a broad sign of inflammation in the body.
You may also see it called the erythrocyte sedimentation rate, or ESR.
What is an ESR test?
An ESR test is a simple blood test. A healthcare professional takes a small blood sample and places it in a vertical tube. The lab then measures how far the red blood cells fall over a set period, usually one hour.
If the cells settle faster than expected, the result may suggest inflammation. If they settle more slowly, the result may be within the expected range or influenced by other factors.
Why is sedimentation rate important?
The sedimentation rate is important because it can help healthcare professionals look for signs of inflammation. It is not specific to one disease, but it can support further evaluation when symptoms or other test results suggest a problem.
Conditions sometimes associated with a raised ESR include:
- Infections
- Autoimmune disorders
- Some cancers, such as lymphoma
- Rheumatoid arthritis
Because the test is nonspecific, it is usually only one part of the diagnostic picture.
What happens during the test?
During the test, blood is usually drawn from a vein in the arm using a sterile needle. The sample is then placed in a standardized tube and left undisturbed.
The lab measures the distance the red blood cells fall in one hour, usually in millimeters per hour (mm/hour).
The procedure is quick, and most people can return to normal activities afterward. Mild bruising or tenderness at the blood draw site can happen.
What does a high sedimentation rate mean?
A high sedimentation rate may suggest inflammation somewhere in the body. It can be seen with infections, autoimmune conditions, and some other illnesses.
Examples mentioned in the original content include:
- Chronic infections
- Rheumatoid arthritis
- Giant cell arteritis
- Multiple myeloma
A high result does not identify the cause by itself. A clinician usually considers symptoms, examination findings, and other tests before drawing conclusions.
Is a sed rate of 2 good?
A sedimentation rate of 2 mm/hour is generally low and may fall within the normal range for many people.
Even so, the meaning of any result depends on age, sex, symptoms, and the laboratory’s reference range. A result that looks low or normal on paper may still need context from a healthcare professional.
What is a normal sed rate for age?
Normal ranges can vary by age and sex. The original content listed these reference values:
| Group | Reference range |
|---|---|
| Men under 50 | 0–15 mm/hour |
| Men over 50 | 0–20 mm/hour |
| Women under 50 | 0–20 mm/hour |
| Women over 50 | 0–30 mm/hour |
These ranges are only a guide. Always check the reference interval printed on the laboratory report.
How do you prepare for an ESR test?
No special preparation is usually needed. People can often eat and drink normally before the test.
It is still sensible to tell the healthcare professional about any medicines or health conditions, because these may affect how the result is interpreted.
What factors can affect the sedimentation rate?
Several factors can influence ESR results, including:
- Age and sex
- Pregnancy
- Chronic disease
- Some medicines, such as corticosteroids
Other blood proteins can also affect how quickly red blood cells settle.
How doctors use ESR results
ESR is best understood as a general clue rather than a final answer. A healthcare professional may use it to support further testing or to follow changes over time.
Because the test is nonspecific, the result should be read alongside symptoms and other investigations.
FAQ: Sedimentation rate definition
▸ What is the meaning of sedimentation rate?
The sedimentation rate is the speed at which red blood cells settle in a tube of blood. It is used as an indirect marker of inflammation.
▸ What does it mean if your sedimentation rate is high?
A high result may suggest inflammation, but it does not show the cause on its own. Further assessment is usually needed.
▸ Is it better to have a high or low sedimentation rate?
In general, a lower result is more reassuring because it may suggest less inflammation. However, interpretation depends on the full clinical picture.
▸ Is a sed rate of 2 normal?
A value of 2 mm/hour is often considered low and may be within the normal range, depending on the laboratory reference range and the person’s age and sex.
▸ Do you need to fast before an ESR test?
No special preparation is usually required for an ESR test, and fasting is not typically needed.
▸ Can medications affect ESR?
Some medicines can affect ESR results or how they are interpreted. It is important to tell the healthcare professional what you are taking.
Safety reminder: If you have symptoms that worry you, or if your ESR result is outside the reference range, speak with a qualified healthcare professional. Do not rely on ESR alone to understand what is happening.
Medical disclaimer
This content is for educational purposes only. It should not be used as a substitute for professional medical advice, diagnosis or treatment. Always ask a doctor, pharmacist or qualified healthcare professional before starting, stopping or changing any medicine.
Sources and verification
The following sources or official references are listed to support verification of the medicine information discussed in this article.
- MedlinePlus: Erythrocyte Sedimentation Rate (ESR)
- NHS: Erythrocyte sedimentation rate (ESR) test
- Mayo Clinic: Sed rate (erythrocyte sedimentation rate)
To improve this article with specific references, add a custom field named _aio_sources in the post editor and write one source per line using: Source title|Source URL.
Medicine information can change and may vary depending on country, product formulation, patient history and professional guidance. Always check official medicine information and ask a healthcare professional for personal medical questions.