Erythrocyte Sedimentation Rate (ESR)

A simple inflammation marker indicating the presence and intensity of systemic inflammatory processes

Erythrocyte Sedimentation Rate (ESR)

Table of contents

Basic data

The Erythrocyte Sedimentation Rate (ESR) measures how quickly red blood cells settle at the bottom of a test tube. A faster-than-normal rate may indicate inflammation in the body caused by infection, autoimmune disease, or chronic conditions.

While nonspecific, ESR remains a valuable and inexpensive tool for detecting inflammatory activity and monitoring disease progression over time. It is often used alongside C-reactive protein (CRP) for a more complete picture of inflammation.

Category: Lab blood panel

Level: Beginner

Usefulness: Medium

Level

Beginner

ESR is considered a basic test suitable for general health screening or initial investigation of symptoms like fatigue, joint pain, or fever. It requires no preparation, is widely available, and provides useful context for understanding inflammation levels.

Usefulness

Medium

ESR is a non-specific but valuable screening marker for systemic inflammation. It helps detect, monitor, and evaluate inflammatory or autoimmune conditions when interpreted with other lab results.
Detects general inflammation

Elevated ESR indicates the presence of inflammation, infection, or autoimmune activity — although it does not pinpoint the exact cause.

Monitors chronic disease progression

Useful in tracking inflammatory conditions like rheumatoid arthritis, lupus, or chronic infections.

Complements other inflammatory markers

ESR is often interpreted alongside C-reactive protein (CRP) for a more comprehensive understanding of inflammatory activity.

How it works

The ESR test measures the rate at which red blood cells (erythrocytes) settle in a vertical tube of anticoagulated blood over one hour.
Blood sample collection

Blood is drawn from a vein into a test tube containing an anticoagulant to prevent clotting.

Sedimentation process

The test measures how many millimeters of clear plasma appear at the top of the column after one hour. Faster sedimentation indicates higher inflammation levels due to altered red cell aggregation.

Measures

ESR is reported as millimeters per hour (mm/h), representing how far red blood cells have fallen in one hour.
ESR value (mm/h)

The primary result — higher values suggest inflammation, infection, or tissue injury.

Age- and sex-adjusted reference ranges

Normal values increase slightly with age and are typically higher in women than in men.

Reliability

ESR is simple and reproducible but affected by several physiological and technical factors, which can reduce specificity.
Repeatability

Consistent under standardized lab conditions but may vary with blood viscosity, temperature, and sample handling.

Sensitivity to conditions

ESR can be elevated due to pregnancy, anemia, or age — even without active inflammation.

Limitations

ESR’s main limitation is its lack of specificity; while a useful screening tool, it cannot distinguish between the many possible causes of inflammation.
Non-specific indicator

Elevated ESR does not reveal the underlying cause — further testing (e.g. CRP, imaging, autoantibodies) is needed for diagnosis.

Influenced by non-disease factors

Age, sex, pregnancy, and anemia can alter ESR values independently of inflammation.

Frequency

Suggested cadence

Typically performed as part of periodic health screening or during active disease monitoring. In chronic inflammatory conditions, it may be repeated every 3–6 months.

Cost

Typical costs

ESR is inexpensive, typically ranging from 15–40 PLN or around $5–10 USD depending on the laboratory.

Availability

Where available

Available in nearly all medical laboratories and included in standard blood panels. Requires only a small venous blood sample.

Preparation

How to prepare

No special preparation is needed. Fasting is optional but may be required if ESR is part of a broader blood test package.

Interpretation

ESR should always be interpreted in context. Elevated results indicate inflammation but not its cause or location.
Mild elevation

Often linked to minor infections, mild inflammation, or post-exercise states.

Moderate to high elevation

Suggests significant inflammation, autoimmune disease, or chronic infection — warrants further investigation.

Alternatives

C-reactive protein (CRP)

A more sensitive and rapidly responsive inflammation marker; often used together with ESR for better diagnostic accuracy.

Fibrinogen test

Measures a key protein in blood clotting and inflammation — correlates with ESR but provides more direct insight into acute-phase response.

FAQ

Can ESR be elevated without disease?

Yes. Factors like aging, pregnancy, or anemia can raise ESR even in healthy individuals.

Which is better — ESR or CRP?

CRP responds faster to acute inflammation, while ESR reflects longer-term or chronic inflammatory processes. Both are complementary.