Erythrocyte Sedimentation rate ESR

Also Known as:      ESR, Sed Rate, Sedimentation Rate, Westergren Sedimentation Rate
 

What is an ESR test?

The erythrocyte sedimentation rate (ESR or sed rate) is a test that indirectly assesses inflammation in the body. The test measures the rate at which erythrocytes (red blood cells) fall (sediment) in a blood sample that has been placed into a tall, thin, vertical tube. When a blood specimen is inserted into a tube, the red blood cells settle out slowly, leaving just a small amount of clear plasma. In the presence of an increased level of proteins, particularly proteins known as acute phase reactants, red cells settle at a faster rate. Inflammation raises the levels of acute-phase reactants, including C-reactive protein (CRP) and fibrinogen, in the blood.

Inflammation is a natural process of the immune system's response. It might be acute, manifesting quickly after a trauma, injury, or infection, or chronic, developing over time with diseases like cancer or autoimmune diseases, in which the immune system mistakenly attacks the body's cells and tissues.

The ESR is not a diagnostic test; it is a non-specific indicator that can be increased in several conditions. It gives you a basic idea of whether or not you have an inflammatory condition.

There have been concerns about the ESR's use in light of newer, more specific tests that have become available. The ESR test is commonly used to diagnose and monitor temporal arteritis, systemic vasculitis, and polymyalgia rheumatic. ESR levels that are extremely high can help with rheumatic disease differential diagnosis. Furthermore, ESR may still be a viable option in some cases, such as when newer tests are unavailable in resource-constrained areas or while monitoring the progression of a disease.

What is the test used for?

The erythrocyte sedimentation rate (ESR or sed rate) is a non-specific, very simple test that has been used for many years to diagnose inflammation in situations like infections, malignancies, and autoimmune diseases. Because an elevated ESR often indicates the presence of inflammation but does not tell the health practitioner where the inflammation is in the body or what is causing it, it is referred to as a non-specific test. Apart from inflammation, other conditions might affect an ESR. As a result, the ESR is frequently combined with other tests, such as C-reactive protein.

ESR is used to diagnose and monitor disease activity and treatment response in various inflammatory disorders such as arthritis, vasculitis, lupus, inflammatory bowel disease, etc. One of the key test results to support the diagnosis is a significantly high ESR.

The ESR test is used to diagnose and monitor children with rheumatoid arthritis or Kawasaki disease in a pediatric setting.

Why and when do you need this test?

An ESR may be ordered when a condition or disease is suspected of causing inflammation in the body. This test can be used to detect a variety of inflammatory diseases. It may be requested, for example, if arthritis is suspected of producing joint inflammation and pain or if inflammatory bowel disease is suspected of causing digestive symptoms.
When a person develops symptoms of polymyalgia rheumatic, systemic vasculitis, or temporal arteritides, such as headaches, neck or shoulder discomfort, pelvic pain, anemia, poor appetite, unexplained weight loss, and joint stiffness, a doctor may recommend an ESR. The ESR can also be ordered regularly to help monitor the progression of certain diseases.

At the same time as the ESR, your doctor may prescribe the C-reactive protein (CRP) test, as well as other general tests like a comprehensive metabolic panel (CMP) or a complete blood count (CBC). Both ESR and C-reactive protein (CRP) are inflammatory indicators. ESR does not change as quickly as CRP does during the beginning of inflammation or as it resolves. CRP is less impacted by other factors than ESR, making it a more accurate indicator of inflammation. However, because ESR is an easily performed test, many healthcare practitioners still utilize ESR as an initial test when they think a patient has inflammation.

What kind of sample is required for the test?

ple is required for the test?A healthcare provider will use a small needle to obtain a blood sample from a vein in your arm.  A small amount of blood will be collected into a test tube or vial once the needle is inserted. When the needle goes in or out, it may sting a little. It usually takes less than five minutes to complete this process.

 Do you need to prepare for the test?

This test does not require any special preparation. However, you should always check with your doctor's office ahead of time to see if you need to follow any pre-test instructions given to you.

Are there any risks to this test?

Having a blood test carries relatively little risk. You or your child may experience minor pain or bruising where the needle was inserted, but most symptoms disappear quickly.

What do the test results mean?

Since ESR is a non-specific inflammatory marker that is affected by various factors, it must be used in conjunction with other clinical findings, the individual's medical history, and the results of other laboratory tests. The health practitioner may be able to confirm or rule out a suspected diagnosis if the ESR and clinical data match. Without any signs of a specific condition, a single elevated ESR is usually insufficient to make a medical decision. A normal result does not, however, rule out inflammation or disease.

Moderately elevated ESR can be caused by:

• Inflammation
• Anemia
• Infection
• Pregnancy
• Aging
• Rheumatoid arthritis
• Rheumatic fever
• Vascular disease
• Inflammatory bowel disease
• Heart disease
• Kidney disease
• Certain cancers

Depending on the person's symptoms, a health practitioner may use other follow-up tests, such as blood cultures. Antinuclear antibody (ANA), rheumatoid factor (RF), fibrinogen, and serum protein electrophoresis are examples of other tests that may be ordered based on your symptoms. The two proteins that cause an increased ESR are globulins and fibrinogen. Your health practitioner may order a fibrinogen level (a clotting protein that is another marker of inflammation) and a serum protein electrophoresis to determine which of these (or both) is causing the elevated ESR based on your medical history, signs, and symptoms.

Even with no inflammation, people with multiple myeloma or Waldenstrom macroglobulinemia (tumors that produce large amounts of immunoglobulins) have very high ESRs. Elevated ESRs may suggest increased inflammation or a poor treatment response when monitoring a condition over time; normal or decreasing ESRs may indicate an effective response to treatment.

A low ESR is associated with diseases that usually prevent red blood cells from sedimenting, such as a high red blood cell count (polycythemia), a significantly high white blood cell count (leukocytosis), and certain protein abnormalities. The ESR is also lowered by changes in red cell shape (such as sickle cells in sickle cell anemia. Women's ESRs are greater than men's, and menstruation and pregnancy might cause temporary increases.

Certain medications and supplements may also influence your results. Oral contraceptives, aspirin, cortisone, and vitamin A are among them. Make sure to notify your doctor about any medications or supplements you're taking.

Related tests: Protein Electrophoresis, Immunofixation Electrophoresis, CRP C Reactive Protein (CRP), Fibrinogen, Rheumatoid Factor (RF), Antinuclear Antibody (ANA), Comprehensive Metabolic Panel