ESR (Erythrocyte Sedimentation Rate) Test

Doctors typically order an ESR test when investigating symptoms such as:

• Unexplained joint pain, stiffness, or swelling
• Persistent low-grade fever without an obvious cause
• Unexplained and unintentional weight loss
• Fatigue that doesn't improve with rest
• Suspected autoimmune or rheumatologic disease
• Monitoring a known inflammatory condition over time

Because ESR is inexpensive and easy to perform, it's frequently used as a first-line screening test before moving on to more specific and costly investigations.

A raised ESR is commonly associated with:

• Rheumatoid arthritis and other autoimmune joint diseases
• Systemic infections of bacterial or viral origin
• Inflammatory bowel disease such as Crohn's disease or ulcerative colitis
• Certain cancers, particularly of the blood and lymphatic system
• Vasculitis, including giant cell arteritis and polymyalgia rheumatica
• Tissue injury or recent surgery

Because so many different conditions can raise ESR, your doctor will always interpret an abnormal result alongside your symptoms, physical examination, and other targeted tests such as CRP or specific antibody panels.

1. No fasting is required — you can eat and drink normally before the test.
2. A single blood sample is drawn from a vein in your arm, usually taking only a minute or two.
3. Let your doctor know if you're pregnant, anemic, or currently menstruating, as these can all cause a mild, non-disease-related elevation in ESR.
4. There's no need to stop any regular medications before this test unless specifically advised.

ESR results rise naturally with age and tend to run higher in women than in men, so your lab's age- and sex-adjusted reference range is the most accurate guide.

A markedly elevated ESR (often above 100 mm/hr) usually points toward a significant underlying process such as infection, malignancy, or an autoimmune flare and typically prompts prompt further investigation.