ESR (Erythrocyte Sedimentation Rate)

What is ESR?

Erythrocyte Sedimentation Rate (ESR) is a simple blood test that measures how quickly red blood cells settle at the bottom of a test tube over one hour. It is a general marker of inflammation in the body.

Key Parameter

Why It Is Done

• Routine health check‑ups
• Evaluation of symptoms such as fever, fatigue, or joint pain
• Monitoring chronic inflammatory conditions (e.g., rheumatoid arthritis, lupus)
• Screening for possible infections or cancers when combined with other tests

Early Detection

ESR can help identify signs of inflammatory or infectious conditions, but it does not diagnose them on its own. A doctor interprets the result together with symptoms, history, and other investigations.

What Abnormal Results Mean

• High ESR may indicate inflammation, infection, autoimmune disease, anemia, or malignancy. Many factors—hydration, pregnancy, medications—can also raise ESR.
• Low ESR is uncommon but can occur with low white‑cell count, low fibrinogen, or certain blood disorders.

Who Should Consider It

Adults and children with unexplained fatigue, fever, joint pain, or a known inflammatory disease. It is also useful when a doctor wants to monitor disease activity or response to therapy.

Quick Summary

ESR is a quick, inexpensive blood test that gives a general sense of inflammation in the body. It is a tool for doctors, not a definitive diagnosis.

Preparation

• Fasting: No fasting required.
• If combined with fasting tests: Follow the longest fasting requirement among the tests.
• Procedure: A healthcare professional will draw a small amount of blood (usually 5–10 mL) from a vein in your arm using a needle. The sample is placed in a special tube and kept upright for one hour.
• What to expect: A brief needle prick; no pain beyond the usual blood draw. You may feel a slight sting.
• Precautions: Stay hydrated, avoid alcohol and strenuous exercise 24 hours before the test if you are also doing other blood tests that require it.
• Note: Confirm specific instructions with your doctor or the lab. This information is educational and not a substitute for professional medical advice.