Contributed by – Healthians Team
What is the ESR test?
An erythrocyte sedimentation rate (ESR) test helps a healthcare practitioner to determine whether or not you are experiencing inflammation. It is not used to diagnose a specific condition, instead, it indirectly measures the degree of inflammation in the body. Usually, depending on the results, a few other health tests are also ordered along with the ESR test to make an accurate diagnosis.
Other names of the ESR test are sedimentation rate test, or sed rate test.
Who should get tested?
You might need an ESR test if you are experiencing symptoms of inflammatory conditions such as arthritis or inflammatory bowel disease (IBD). They include:
- Joint pain or stiffness
- Headaches
- Abnormal weight loss
- Pain in the shoulders, neck, and pelvis
- Symptoms of digestive disorder, such as diarrhea, blood in the stool, abnormal abdominal pain
Why is the ESR test needed?
ESR test is a relatively simple and non-specific test used to detect inflammation and associated conditions such as infections, arthritis, and autoimmune diseases. It actually measures the rate at which erythrocytes (red blood cells) fall when a small sample of blood is placed into a tall, thin, vertical tube. The results are depicted based on the clear fluid (plasma) present at the top portion of the tube after one hour.
Normally, red blood cells settle at a relatively low rate and leave very little clear plasma. However, when certain proteins, such as C-reactive protein and fibrinogen, increase in blood in response to the inflammation, red blood cells clump together which in turn increases the rate at which they fall.
ESR results provide general information about the presence or absence of inflammation in the body and the levels may be elevated due to a number of conditions. Hence, other tests are often ordered along with it.
What does ESR test results mean?
The ESR result is reported as the millimeters of clear fluid present at the top portion of the tube after an hour. For your reference, the following table shows the values of a normal ESR test result:
| MEN | WOMEN | |
| UNDER AGE 50 | 0 – 15 mm/hr | 0 – 20 mm/hr |
| OVER AGE 50 | 0 – 20 mm/hr | 0 – 30 mm/hr |
The higher the number, the higher the likelihood of inflammation. Conditions associated with a higher rate include:
- Advanced age
- Pregnancy
- Anaemia
- Kidney diseases
- Obesity
- Thyroid diseases
- Certain cancers
Autoimmune conditions associated with a higher rate include:
- Lupus
- Arthritis
- Rare form of cancer
- Temporal arteritis
- Allergic or necrotizing vasculitis
And, infections that can cause elevated ESR levels are:
- Bone infections
- Heart infections
- Rheumatic fever
- Skin infections
- Systemic infections
- Tuberculosis
Conditions associated with having low levels of ESR include:
- Congestive heart failure
- Low plasma protein
- Leukocytosis
- Bone marrow disorder
- Sickle cell anaemia
Note that ESR test results are non-specific. Having high or low ESR levels doesn’t necessarily mean the presence of the above-mentioned conditions. Further tests based on the symptoms should be performed to make a specific diagnosis. Besides, having normal ESR levels doesn’t rule out inflammation. Therefore, always get your reports checked by a doctor to understand what your results actually mean for you.
How is the test done?
A small sample of blood is needed to perform the ESR test. It is usually drawn from a vein in the arm. The process is relatively quick and painless. At most, you might feel a prick of the needle. Once an adequate amount of blood is drawn, a bandaid is placed over the punctured site to prevent any infection. The sample is then sent to a lab for testing.
Fasting or any other kind of special preparation before the sample collection is usually not necessary. However, intimate your doctor about any existing medical conditions you may have and medications you take as they can influence your test results.
