Erythrocyte Sedimentation Rate (ESR) Test

Erythrocytes are a synonym for red blood cells. Erythrocytes have peculiar properties in terms of size, thickness and shape. When blood is added to a test tube, red blood cells (erythrocytes) drop and settle at the bottom of this tall, thin tube.

ESR test measures how quickly erythrocytes settle at the bottom of a test tube. Red blood cells settle at a lower rate under normal conditions. A higher-than-normal rate could suggest that the body is fighting an inflammatory process.

The inflammatory reaction is a natural response of the immune system. Illness, infection or accident can be the cause of this inflammatory response. Inflammation can be due to the presence of a long-standing disease, an immunological disorder or other medical illnesses.

Erythrocytes (red blood cells) might clump together because of an inflammatory response. In an inflammatory process, red blood cells become dense and thick. So, erythrocytes settle to the bottom more quickly than other blood cells because they are dense.

ESR results do not diagnose any diseases, but they can confirm the presence of inflammatory reactions in the body.

ESR is used as an indicator of inflammatory problems. ESR reports help to monitor an existing medical condition. ESR helps doctors to monitor the progress of inflammatory diseases. With ESR values, doctors can also track how a medication is working in treating a particular disease.

The ESR test isn’t a stand-alone diagnostic tool. ESR is used for the diagnosis of an inflammatory response. Because an ESR test can’t diagnose the underlying cause of inflammatory response, other blood tests, such as the C-reactive protein (CRP) test and specific diagnostic tests, are often used in conjunction with it.

If ESR results are abnormal, doctors will need more diagnostic tests. In such a situation, doctors may likely ask for more lab tests before reaching a final diagnosis.

ESR results are slightly higher in women than in men. Women during pregnancy and menstruation have slightly higher ESR. Old age is correlated with ESR levels. People above fifty have higher ESR than those below fifty years.

Other names of ESR test

• Erythrocyte sedimentation rate
• Westergren sedimentation rate
• Sed rate
• Sed rate by modified Westergren
• Sedimentation rate

What does the ESR test detect/measure and whom is this prescribed for?

The ESR values are included in tests that detect inflammatory responses in the body. The test measures the rate at which red blood cells fall through the blood plasma and cluster together at the bottom of a test tube in one hour.

The red blood cells are negatively charged ions. So they repel each other. The negative charge prevents these cells from forming clusters and settling down. High blood viscosity lowers the rate at which erythrocytes sediment.

There is an elevation in ESR levels before the onset of acute inflammatory conditions. ESR test is suggested for people presenting with signs of an inflammatory reaction, such as:

• Headaches
• Joint stiffness
• Swollen joints
• Painful joints
• Pain in shoulders
• Loss of appetite
• Weight loss for no reason
• High fever
• Chills with or without fever
• Stiffness in muscles
• Neck pain
• Anaemia
• Unexplained weakness
• Unexplained weight loss

ESR is used for the diagnosis of the following :

• Osteomyelitis
• Cancer
• Arteritis
• Systemic lupus erythematosus
• Polymyalgia rheumatica
• Rheumatoid arthritis
• Systemic vasculitis
• Renal disorders
• Pericarditis
• Endocarditis
• Lymphatic cancer
• Multiple myeloma
• Tuberculosis

If your doctor suspects any of the conditions listed above, they may order an ESR test. The ESR test is also recommended to track the course of treatment for the illnesses indicated above.

The ESR test is applicable for males and females, both adults and children. Some medicines like contraceptives, aspirin, cortisone, vitamin A and conditions like pregnancy and obesity may cause a false elevation in ESR levels. Inform your doctor about any current medications.

The analysis of ESR is based on a blood sample. A simple blood test determines the ESR.

Test Preparation

Fasting is not essential for this test. A lab technician will collect blood samples at the hospital or in the laboratory. In patients already admitted for treatment, samples are collected at the bedside.

A syringe needle is used for the collection of the blood sample. The phlebotomist will collect blood from an arm vein. A small amount of blood will be collected in a test tube after needle insertion and the needle prick might sting a little.

The procedure of ESR takes about five minutes in total. The spot of syringe insertion on your arm may be sensitive for a few hours after the procedure of ESR. The individual will be able to resume their usual activities after the sample collection.

Test inclusions: What parameters are included?

The ESR test only includes one parameter (ESR level)). This estimation provides insight into the body’s inflammatory response. The readings will be within normal limits if there is no severe inflammation in the body.

ESR values will be higher if the body is fighting an infection or recovering from trauma. ESR values will be excessively high with serious health issues. ESR levels are used to track treatment and management.

ESR test means the rate of red blood cells settling down in blood plasma. The results of ESR are measured in millimetres of red blood cell sediment in one hour.

The ESR normal range is as given below:

The normal values and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

When the ESR range falls under normal limits, it is said to be negative ESR. In conditions where ESR is above the normal limits, results are said to be positive ESR.

If ESR results aren't within the normal range, it doesn't necessarily indicate an underlying disease. Factors like age can alter ESR results. A moderately high ESR range could indicate pregnancy, menstruation or anaemia. These physiological variations are considered negative ESR.

ESR results may also be influenced by certain medications and supplements. Oral contraceptives, aspirin, cortisone and vitamin A are some medications that show a false positive ESR.

An ESR range above or below normal limits does not diagnose disease conditions. It simply detects a potential inflammation in the body. An abnormal ESR result gives an alert to the need for further investigation. The result of ESR may be a false positive with physiological variations.

If the ESR value is higher, it may be related to an inflammatory condition, such as:

• Infection
• Autoimmune diseases
• Rheumatic fever
• Vascular disease
• Inflammatory disorders
• Heart disease
• Kidney disease
• Cancer
• Anaemia
• Obesity
• Thyroid disease

ESR higher than the normal range could be due to the following autoimmune diseases:

• Systemic lupus erythematosus - An autoimmune disorder involving joint pain and skin lesions.
• Rheumatoid arthritis - An autoimmune joint disease that affects smaller joints.
• Temporal arteritis - A condition with inflammation of the temporal artery.
• Polymylgia rheumatica - A musculoskeletal disorder.
• Hyperfibrinogenemia - A protein disorder.
• Allergic vasculitis

The result of ESR can also diagnose some infectious illnesses like:

• Bone infections
• Heart infections, such as myocarditis, pericarditis and endocarditis.
• Rheumatic fever
• Skin Infection
• Tuberculosis (TB)

ESR is one piece of data that doctors can use to assess an individual's health status. Several factors can influence the characteristics of blood. These factors impact the rate at which red blood cells sink in a sample of blood. The complicating factors are old age, anaemia, pregnancy and obesity.

Therefore, in people with these conditions, ESR reports should be interpreted carefully.

If the ESR reports show positive ESR, consult with your doctor to determine the cause of the symptoms. Make sure to notify the doctor of your medical history to avoid misinterpretation. If ESR readings are abnormally high, your health care provider will suggest additional tests for the final diagnosis.

Infection, Tuberculosis, Myocardium, Lymphoma, Rheumatoid Arthritis, Systemic Lupus Erythematosus, Cancers 

Typically, an Erythrocyte Sedimentation Rate (ESR) test is priced in the range of INR 149 to INR 219. However, the cost can vary based on the city and the laboratory chosen. To provide a more detailed overview, here are the average cost of ESR test in several major Indian cities: