ESR tests are commonly conducted as a part of regular blood tests. These tests measure the time it takes for red blood cells to settle at the bottom of a test tube, with a high settling rate indicating increased inflammation. Generally, red blood cells tend to settle at a slow rate. If the results of the ESR test indicate a high settling rate (i.e., elevated ESR levels), it may suggest an underlying medical condition, which could present as elevated ESR symptoms. Before delving into the causes of raised ESR levels, it is important to understand the purpose of the ESR test and its practical significance.

What is an ESR Test?

The ESR or Erythrocyte Sedimentation Rate test quantifies the speed at which erythrocytes (red blood cells) settle at the base of a blood specimen. The results of the ESR test cannot be used to diagnose a specific disease, as various health conditions can lead to either high or low ESR values. Doctors consider the ESR test a nonspecific diagnostic tool, as it merely indicates the presence of an inflammatory response in the body. To make a comprehensive diagnosis, healthcare professionals typically combine ESR test results with other laboratory tests, clinical observations, and a patient's medical history.

Purpose of the ESR Test

The primary goal of an ESR sedimentation rate is to identify elevated levels of inflammation within the body. An ESR may be prescribed by a health care provider if an individual exhibits signs and symptoms indicative of an inflammation-related condition. These signs and symptoms may vary depending on the individual's condition, but may include:

• Neck or shoulder pain
• Headaches
• Weight loss
• Unexplained fever
• Joint stiffness
• Loss of appetite
• Anaemia

Additionally, an ESR test may be necessary if a patient has been diagnosed with a disease that could be a reason for high ESR in blood.

Types of ESR Tests

There are two techniques for measuring your erythrocyte sedimentation rate:

• Westergren Method: The Westergren method is the most commonly used ESR method. In this test, blood is drawn into a Westergren-Katz tube until it reaches a level of 200 millimeters (mm). The tube is then stored vertically at room temperature for an hour. The measurement involves determining the distance between the top of the blood mixture and the top of the sedimentation of red blood cells (RBCs).
• Wintrobe Method: The Wintrobe method closely resembles the Westergren method, with the key difference being the use of a tube that is 100 mm long and thinner. However, a drawback of this method is its lower sensitivity compared to the Westergren method.

How is an ESR Done?

A physician will draw a blood sample from the patient's vein and send it to the laboratory. Laboratory technicians will carefully transfer the sample to a vertical test tube, allowing red blood cells to settle at the bottom. A clear, yellowish liquid, known as blood plasma, will accumulate at the upper portion of the tube. The test's outcome will be determined by measuring the amount of plasma collected at the upper end of the test tube after one hour. High ESR in blood are expressed in millimetres per hour (mm/hr).

Individuals with inflammatory conditions often display elevated ESR levels in their blood reports. Inflammatory conditions trigger a response in the body, leading to an increase in the concentration of proteins within the blood. Consequently, red blood cells aggregate and settle more rapidly.

What do high ESR Levels mean?

The ESR blood test results will typically be compared to other test results to confirm a probable diagnosis. Physicians will consider the signs and symptoms a patient exhibits, along with their personal and family medical history.

An extremely high ESR value of more than 100 mm/hr may indicate one of the following conditions:

• Multiple myeloma: a type of cancer affecting plasma cells.
• White blood cell cancer, also known as Waldenstrom's macroglobulinemia.
• Hypersensitivity Vasculitis: a condition where the body's allergic reaction causes inflammation of blood vessels.
• Temporal arteritis or polymyalgia rheumatica.

A slightly higher erythrocyte sedimentation rate does not necessarily indicate a health issue in an individual. However, individuals with slightly high CRP and ESR may be associated with some of the following conditions:

• Rheumatoid arthritis
• Systemic infection
• Reduced number of red blood cells or anaemia
• Thyroid issues
• Kidney disease
• Certain forms of cancer, such as lymphoma
• Abnormalities in red blood cells
• Tuberculosis
• Bone infection
• Heart infection

When does the doctor recommend an ESR Test?

The ESR blood test detects and quantifies inflammation in the body in general. However, the test does not determine the exact source of inflammation. The doctor will likely use the test in combination with other tests to identify the underlying cause of the symptom. If an individual already has an inflammatory condition, the doctor may use ESR to confirm the effectiveness of the current treatment plan.

The ESR test may be utilised by medical professionals to identify inflammatory conditions such as:

• Temporal arteritis
•  Some types of cancers
•  Autoimmune diseases
•  Infections

Healthcare professionals can use the ESR test to track autoimmune inflammatory diseases like:

• Rheumatoid arthritis (RA)
• Systemic lupus erythematosus (SLE)

ESR Results

The ESR test results are obtained by measuring the remaining amount of plasma in the test tube after one hour. Since the test is not intended to diagnose a specific condition, physicians must interpret the results in conjunction with other clinical data to accurately diagnose the patient and determine the presence of a disease. The normal reference range of ESR results for males is 1–13 millimetres per hour (mm/hr), and for females, it is 1–20 millimetres per hour. These values may vary depending on the individual's age.

What is the normal range for ESR Levels?

ESR levels correspond to elevated protein levels in the blood, resulting in an increase in the rate at which Red Blood Cells (RBCs) clump together. The ESR test works by measuring the distance in millimetres (mm) from the clear liquid at the tip of the tube to the red blood cells (RBCs) after one hour. The normal values for ESR rates are as follows:

• 0 to 15 mm/hour in men under 50 years of age
• 0 to 20 mm/hour in men aged 50 and above
• 0 to 20 mm/hour in women under 50 years of age
• 0 to 30 mm/hour in women aged 50 and above

What symptoms indicate you might need an ESR test? 

An ESR test may be necessary if you encounter signs of inflammatory conditions like arthritis or inflammatory bowel disease (IBD). These symptoms can include:

• persistent joint pain or stiffness lasting over 30 minutes in the morning,
• headaches, especially those accompanied by temple pain and vision alterations,
• unintended weight loss,
• discomfort in the shoulders, neck, or pelvis,
• gastrointestinal symptoms, such as:
  • diarrhea
  • fever
  • presence of blood in stool
  • unusual abdominal pain

What can cause High ESR Levels?

There can be various reasons for high ESR levels, with the most common being inflammatory diseases. Some of these conditions include:

• Systemic inflammatory infections: Inflammatory disorders that have spread to the blood.
• Increased ESR count due to minor illnesses such as colds, wounds, and other occurrences.
• Tissue injury or ischemic tissue injury (tissue with insufficient blood supply).
• Generally, ESR tends to increase with age.
• Traumatic events or accidents

What should I do if I have High ESR Levels?

After receiving an ESR medical report showing elevated ESR levels, the best course of action is to wait for the doctor to make a proper diagnosis based on other factors such as gender, age, and general health. Individuals with elevated ESR levels may not always have underlying medical conditions that require treatment. 

Elevated ESR levels may also be associated with pregnancy, menstruation, or ageing. If the physician determines that the individual is suffering from a medical condition, he or she is likely to prescribe a treatment tailored to the individual's specific condition. 

Reference:
https://www.medicalnewstoday.com/articles/323057#results
https://www.healthline.com/health/esr#uses
https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=erythrocyte_sedimentation_rate