Erythrocyte Sedimentation Rate Test (ESR Test)

Overview

A blood test called the Erythrocyte Sedimentation (ESR) test may be recommended if your doctor suspects that there is a high level of inflammation. This test measures how fast red blood cells sink to the bottom of a tube. High levels of inflammation are indicated by a rapid rate of settlement.

An ESR test is also known as a sedimentation test or SED test. It doesn’t diagnose any specific condition. It helps your doctor determine if you are experiencing inflammation and what additional testing might be necessary. You can also use the ESR test to detect if you have any inflammatory diseases.

Find out more about the ESR test and what it could mean. Before you get your blood drawn, talk to your doctor.

How Does The ESR Blood Test Work?

An ESR test measures the rate at which your red blood cells (RBCs) fall to the bottom of a test tube. The blood sample for this test is measured over the course of an hour.

When you’re experiencing inflammation, it can affect your RBCs in several ways. First, your RBCs cling together, forming clumps. This clumping affects the rate at which RBCs sink inside a tube where a blood sample is placed.

Also, if you have an acute infection or chronic inflammation, there may be more proteins in your RBCs. This can cause them to settle quicker. The faster and further the cells sink toward the bottom of a test tube, the more likely it is that inflammation is present.

In all, your ESR number is based on the rate that your RBCs settle. The faster this happens, the higher your ESR — and the more inflammation is likely to be present in your body.

What Is The ESR Blood Test?

The ESR test measures how fast your red blood cells (RBCs), fall to the bottom in a test tube. This test takes one hour to measure the blood sample.

Inflammation can cause damage to your RBCs in many ways. Your RBCs can cling together and form clumps. This clumping can affect the rate at which RBCs sink in tubes where a blood sample has been placed.

You may also notice an increase in the number of proteins in your RBCs if you have chronic inflammation or acute infection. They may settle faster due to this. Inflammation is more likely to be present the faster cells sink towards the bottom of the test tube.

Your ESR number is determined by the rate at which your RBCs settle. Your ESR will increase the faster your RBCs settle. This can also lead to more inflammation in your body.

Conditions That Cause Inflammation:

Your doctor can use the ESR test to diagnose conditions that can cause inflammation such as

• Temporal arteritis
• Autoimmune diseases
• Cancers
• Infections

Monitoring For Inflammatory Conditions

An ESR test is a tool that can be used by healthcare professionals to monitor conditions such as

• Rheumatoid arthritis (RA)
• Systemic Lupus Erythematosus (SLE)
• If you are pregnant, your doctor may order the test.
• Some types of arthritis
• Certain muscle and connective tissue issues, such as polymyalgia.

Are You Experiencing Any Of These Symptoms?

If you have symptoms such as arthritis (IBS) or inflammatory bowel disease, an ESR test may be necessary. You might experience the following symptoms:

• Joint pain or stiffness lasting longer than 30 minutes during the morning
• Headaches, especially those that are associated with pain in your temples or vision changes, can be very serious.

• Unintentional weight loss
• Pain in the neck, shoulders, or pelvis
• Digestive symptoms, such as
  • Diarrhoea
  • Fever
  • Blood in your stool
  • Unusual abdominal pain

How Can You Prepare For An ESR Test?

It is not difficult to pass the ESR test. If you are taking any medication, tell your doctor. You may be asked to temporarily stop using it before the test.

ESR test results may be affected by certain medications. Steroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and statins can cause falsely lower ESRs. You should not stop taking prescription medications unless your doctor has instructed you otherwise.

How Is The ESR Testing Procedure Performed?

1. The test requires a simple blood draw. The test should only take a few minutes.
2. First, the skin is sanitized right above your vein.
3. Next, a needle will be inserted to collect your body’s blood.
4. Once the blood is collected, the needle is removed and the puncture site is covered to stop bleeding.

Your blood sample will be taken to the lab. There, your blood will then be placed in a tube that is long and thin. It will sit for an hour. The laboratory technician will evaluate the RBCs sinking into the tube and the speed at which they are sinking.

An abnormal protein can appear in your blood due to inflammation. These proteins can cause your RBCs to clump together. This causes them to fall faster.

Additional Tests That Can Be Done At The Same Time:

A C-reactive protein (CRP) test may be ordered by your doctor along with your ESR test. CRP tests can measure inflammation, but they also provide information that may help predict your risk for developing Coronary Artery Disease (CAD), and other cardiovascular diseases. Your doctor may also order a Complete Blood Count (CBC), to check for signs of infection or inflammation.

How Long Does It Take For Results To Appear?

Although wait times may vary, most labs that perform the test will provide results within a few days. Your results and any next steps will be provided by your doctor or nurse.

Is There Any Risk Associated With An ESR Test?

An ESR test is not associated with any potential risks. There may be a minimal risk if your blood is drawn. Some of the possible complications include:

• Bleeding, from very mild to severe
• Fainting
• Hematoma
• Bruising
• Infection
• Inflammation of the vein
• Tenderness
• Lightheadedness

When the needle pokes into your skin, you’ll feel mild to moderate pain. After the test, you might feel some throbbing at your puncture site. 

You may feel uncomfortable looking at blood. Before you have your blood drawn, talk to your doctor or technician.

What Are The Two Types Of ESR Testing?

Two methods can be used to measure your erythrocyte segregation rate:

Westergren method

This is the most popular ESR method. This type of test involves drawing blood into a Westergren Katz tube until your blood level reaches 200 mm (mm).

The tube is kept vertically, and it sits at room temperature for one hour. It is determined the distance between the top layer of blood mixture and the top layer of sedimentation of RBCs.

Wintrobe method

The Wintrobe method works similarly to the Westergren, but the tube is shorter and 100 mm longer.

This method is less sensitive than the Westergren method.

How Do ESR Test Results Normally Look?

ESR test results can be measured in millimeters per hour (mm/hr). The more you have, the greater the chance of inflammation. Females have higher ESR levels.

The Normal ESR Test Results are as follows:

ESR tests that show a higher than 100 mm/hr may indicate an active disease such as diabetes or cancer.

Understanding Abnormal ESR Results

An abnormal ESR result does not diagnose any disease. This test identifies inflammation potential in your body and suggests a need for further investigation.

A value of 0.01 would be considered abnormally low. Because these tests fluctuate, it’s difficult to give an exact value. What is considered to be too low could vary from person to person?

The results of this test are not always reliable and meaningful. Your results can be affected by many factors, including

• Older age
• Medication use
• Pregnancy
• Menstruation

Also Read: Why Should a Beta-hCG Blood Test Be Done

While some abnormal ESR test results can be more severe than others, many are not too serious. If your ESR test results are unusual, it’s not a reason to panic.

Instead, consult your doctor to determine the cause of your symptoms. If your ESR results are abnormally high or low, they will usually order follow-up tests.

High ESR Test Results

A high ESR test result can be caused by many factors. A higher ESR test result is often associated with the following conditions:

• Systemic and localized Inflammatory and Infectious Diseases (Local or Widespread)
• Tissue injury (or ischemia) is a condition that causes a lack of blood supply to tissue.
• trauma
• Certain types of cancers, including multiple myeloma and lymphoma, are possible
• Older age
• Pregnancy
• Anaemia
• Kidney disease
• Diabetes
• Heart disease
• Blood or vascular disease
• Blood vessel inflammation (vasculitis)
• Obesity
• Thyroid disease

A high ESR, even if there is no inflammation, can be a sign of cancerous tumors.

Autoimmune conditions

ESR results that are higher or less than normal can also be associated with autoimmune disorders, such as

• Lupus
• Certain types of arthritis, such as RA, are also known.
• Waldenstrom’s macroglobulinemia is a rare form of cancer.
• Temporal arteritis is a condition where your temporal blood vessels become inflamed.
• Polymyalgia Rheumatica is a condition that causes joint and muscle pain.
• Hyperfibrinogenemia is a condition where there is too much protein fibrinogen.
• Necrotic or allergic vasculitis

Infections

There are some types of infections that can cause ESR test results higher than normal.

• Bone infection
• Heart infections can cause myocarditis, pericarditis, and endocarditis. These conditions affect the lining of your heart.
• Rheumatism fever
• Skin infection
• Systemic infections
• tuberculosis (TB)

Low ESR Test Results:

Low ESR results could be caused by:

• Congestive heart failure (CHF)
• Hypofibrinogenemia is a condition where there is not enough fibrinogen in the blood.
• Low plasma protein (caused by kidney disease or liver problems)
• Leucocytosis is a condition that causes a high level of white blood cells (WBC).
• Polycythemia vera is a bone marrow disorder that causes excess RBC production.
• A genetic disease that affects the RBCs is known as sickle cell anemia.

What Next Steps After An ESR Test?

Your doctor may order additional tests based on your results. This could include a second ESR test to confirm the first. These tests could help your doctor determine the cause of your inflammation.

ESR tests are also available if you have an underlying condition that is causing high ESR levels. These tests can be used to monitor ESR levels and measure the effectiveness of treatments.

An Underlying Condition

Your doctor may refer you to a specialist if they suspect that there is an underlying condition that could be causing your high ESR.

Inflammation

Your doctor may recommend the following treatment if they detect inflammation:

1. Taking a nonsteroidal anti-inflammatory drug (NSAID), like Ibuprofen (Advil or Motrin), or Naproxen [Aleve, Naprosyn]
2. Corticosteroid therapy for inflammation

Infection

Your doctor may prescribe antibiotics to treat inflammation caused by bacterial infections.

Final Takeaway

• Your doctor may order an ESR test to measure your body’s inflammation. This test is often combined with other lab tests to diagnose or rule out various inflammatory conditions.
• Your doctor may order additional testing depending on the results.
• Your ESR levels may be affected by a variety of chronic and acute conditions, including autoimmune diseases, cardiovascular problems, and infections, as well as certain cancers.
• If you have any concerns, talk to your doctor. They may recommend an ESR test based on your medical history, symptoms, and physical exam.

FAQs

Sources

• Alende-Castro V, et al. (2019). Factors influencing erythrocyte sedimentation rate in adults.
  journals.lww.com/md-journal/fulltext/2019/08230/factors_influencing_erythrocyte_sedimentation_rate.19.aspx
• Blood test: Erythrocyte sedimentation rate (ESR). (2021).
  kidshealth.org/en/parents/test-esr.html
• Tishkowski K, et al. (2021). Erythrocyte sedimentation rate.
  ncbi.nlm.nih.gov/books/NBK557485/