What Is An ESR?
The ESR (erythrocyte sedimentation rate) test measures how quickly red blood cells (erythrocytes) settle at the bottom of a test tube over an hour. Normally, red blood cells settle slowly, but faster rates may indicate inflammation or disease in the body. The test is often used as a marker for conditions like infections, autoimmune disorders or cancers.
ESR is often used to:
- Monitor inflammation levels over time.
- Assist in diagnosing diseases like arthritis, lupus, or temporal arteritis.
- Evaluate unexplained symptoms such as fever, muscle pain, or weight loss.
ESR is not a disease specific test but is used to monitor inflammation and is used as a starting point in diagnosing underlying health problems.
How is the Test Performed?
The ESR test requires a blood sample:
Sample Collection
Blood is drawn from the vein of your arm.
Lab Analysis
The blood sample is then placed in a tall, thin test tube and left undisturbed for one hour. During this time, the red blood cells settle at the bottom of the tube. The rate at which they settle is measured in millimeters per hour (mm/hr). The faster the cells settle, the higher the ESR value, indicating inflammation.
Result Calculation
Results are normally available within a few hours.
What are the symptoms that prompt this test?
The most common symptoms that prompt this test are:
Adults
- Persistent fatigue
- Unexplained fever
- Joint pain or stiffness
- Unexplained weight loss
- Muscle pain or tenderness
- Severe headaches
- Jaw pain while eating
- Sudden vision changes
Children
- Unexplained fever
- Weakness or fatigue
- Persistent joint or muscle pain
- Rash with no known cause
What are Normal Ranges for This Test?
Men – 0 to 15 mm/hr
Women – 0 to 20 mm/hr
Values may vary slightly depending on age and lab standards. Pregnant women may naturally have higher ESR levels.
**The above-given reference value is for general guidelines only and should not be considered as a diagnosis. Your healthcare provider will give you the correct interpretation of the results. **
What Happens if Test Results Show Abnormal Levels?
Abnormal ESR results indicate inflammation but do not specify its cause. Elevated levels may prompt:
- Further tests like CRP (C-reactive protein), complete blood count (CBC) or specific autoimmune tests.
- Imaging studies such as X-rays or ultrasounds to locate inflammation.
- Referral to a specialist, such as a rheumatologist, for in-depth evaluation.
Treatment depends on the underlying condition causing the abnormal result.
