Inflammation is the body's natural response to infection, injury, or certain medical conditions. While it plays an important role in healing, ongoing inflammation may sometimes indicate an underlying health condition that requires further evaluation. The Westergren test is one of the most commonly used blood tests to assess inflammation, helping doctors gather additional information alongside a person's symptoms and other investigations. Although the test cannot diagnose a specific disease, it helps identify whether inflammation is present and supports doctors in monitoring a wide range of conditions over time.

What Does the Westergren Test Measure?

The Westergren test measures the erythrocyte sedimentation rate (ESR), the rate at which red blood cells settle to the bottom of a vertical tube over one hour. The test was developed by Swedish physician Dr. Alf Westergren, and it uses a standardised tube and a fixed ratio of sodium citrate to blood. It is recognised by the International Council for Standardisation in Haematology (ICSH) as the reference method for ESR measurement.

The test does not diagnose a specific illness. Instead, it acts as a general marker of inflammation. Doctors interpret the result alongside a person's medical history, symptoms, and other laboratory findings before deciding whether additional investigations are needed.

Conditions That May Require a Westergren Test

A doctor may advise a Westergren test when assessing symptoms or monitoring conditions associated with inflammation. Common situations include:

• Persistent fever without an obvious cause

• Joint pain or stiffness

• Unexplained fatigue or weakness

• Monitoring inflammatory conditions such as rheumatoid arthritis or polymyalgia rheumatica

• Supporting the evaluation of conditions, including lupus or temporal arteritis

• Assessing response to treatment in chronic inflammatory disorders

Since ESR is a non-specific marker, the result is always interpreted alongside other clinical findings rather than on its own.

What Happens During the Westergren Test?

The Westergren method follows a standardised procedure to ensure accurate and reproducible results:**

• Collecting a blood sample from a vein in the arm

• Mixing the sample with sodium citrate to prevent clotting

• Filling a calibrated Westergren tube with the sample

• Placing the tube upright for one hour

• Measuring how far the red blood cells settle, reported in millimetres per hour (mm/hour)

**Note: A qualified healthcare professional should make any decisions regarding diagnosis or treatment. 

The test generally does not require fasting. However, it is important to inform your healthcare provider about any pregnancy, recent illnesses, or medications you are taking, as these may affect ESR values. For reliable laboratory testing, it is important to choose an accredited diagnostic provider that adheres to standardised quality protocols to ensure accurate, dependable test results.

Normal Westergren ESR Ranges

Normal ESR values vary according to age and gender. The usual reference ranges include:*

• Men under 50 years: Up to 15 mm/hour

• Men over 50 years: Up to 20 mm/hour

• Women under 50 years: Up to 20 mm/hour

• Women over 50 years: Up to 30 mm/hour

• Children: Up to 10 mm/hour

• Newborns: Up to 2 mm/hour

These values serve only as general reference ranges. The significance of an ESR result depends on the individual's overall clinical picture and should always be interpreted by a qualified healthcare professional.

*Note: This information is general and should not replace professional medical advice.

Interpreting High and Low ESR Results

An elevated ESR suggests that inflammation may be present somewhere in the body, but it does not identify the exact cause. Higher ESR values may be associated with:

• Bacterial, viral, or fungal infections

• Autoimmune conditions such as rheumatoid arthritis or systemic lupus erythematosus

• Chronic inflammatory bowel disease

• Certain cancers, including lymphoma and multiple myeloma

• Kidney disease

• Pregnancy, where mild elevations can occur naturally

Very high ESR values often lead doctors to recommend additional investigations to determine the underlying cause. 

Choosing an Accredited Diagnostic Laboratory

Since the Westergren test depends on precise laboratory techniques, selecting a trusted diagnostic provider is important. Proper sample handling, accurate anticoagulant ratios, and controlled testing conditions all contribute to reliable results that support clinical decision-making. Trusted NABL-accredited laboratories such as Lupin Diagnostics offer Westergren ESR testing and comprehensive inflammation panels across India. With standardised testing protocols and free home sample collection in major cities, patients can access reliable diagnostic services with added convenience.

Conclusion

The Westergren test remains the internationally accepted method for measuring erythrocyte sedimentation rate because of its consistency and reliability. Although it cannot diagnose a specific condition, it provides valuable information that helps doctors assess inflammation and determine whether further evaluation or ongoing monitoring is appropriate. If your doctor has recommended an ESR test, choosing a trusted diagnostic laboratory, such as Lupin Diagnostics, can help you obtain accurate results. You can also explore their health resources to learn more about diagnostic tests and preventive healthcare.