The ESR (or erythrocyte sedimentation rate) is the sedimentation rate of erythrocytes (red blood cells), i.e. the cells that carry oxygen from the lungs to the tissues.
Specifically, the test measures the time it takes for red blood cells to separate from the liquid part of the blood (plasma) and settle to the bottom of a test tube. The result is measured by checking how many millimeters of plasma are present in the upper part of the tube after one hour.
The examination is useful for identifying the possible presence of an inflammatory state, although it is not very specific and not very sensitive. In fact, it does not provide precise information on the causes of inflammation, but it is still a widely used test, also because it is cheap and easy to perform.
The faster the red blood cells are deposited, the higher the ESR, thus becoming an indicator of the body’s response in the acute phase. The causes of high or, conversely, low ESR are many and can hide more or less serious conditions.
Usually, RBC sedimentation rate is recommended when inflammatory reactions, infections, or autoimmune diseases are suspected, but it is not a diagnostic test for a particular disease. Therefore, it is only an indicator that something is wrong with the body and serves the doctor to recommend further diagnostic investigations.
What is ESR and how does it work
Red blood cell sedimentation rate (ESR or ESR) is a blood test that can reveal inflammatory activity in the body.
The increase in fibrinogen (a protein produced by the liver which indicates the blood’s ability to clot) and immunoglobulins (immune system cells) causes red blood cells to stick together and form clusters called ‘Rouleaux’. The erythrocytes therefore appear as heavy piles of coins which fall faster, increasing the value of the ESR.
It is not a stand-alone diagnostic tool, but it can help the doctor make the correct diagnosis or monitor the progression of an inflammatory disease.
When the blood is collected and placed in a tall, thin tube, the erythrocytes (red blood cells) slowly settle at the base, thus taking the shape of a column. Inflammation, likewise, can cause red blood cells to accumulate, and since these clusters are denser than individual red blood cells, they sink to the bottom of the tube faster.
The sedimentation rate test therefore measures how far red blood cells fall into a test tube over an hour.
The lower the red blood cells, the greater the inflammatory response of the immune system.
ESR is a non-specific test. It is used in a wide range of infectious, inflammatory, degenerative and malignant diseases associated with changes in plasma proteins, especially when it comes to increases in fibrinogen, immunoglobulin and C-reactive protein.
At the same time, the ESR is influenced by many other factors including: anemia, pregnancy, treatment with anti-inflammatory drugs.
What is the ESR analysis for?
An abnormal ESR result does not diagnose any particular disease. The test only identifies an ongoing inflammation in the body. Many factors, such as age or medication use, can change or influence results, which is why reading and interpreting them should always be performed by a competent physician.
So, the specialist may recommend that you have an ESR test if you have symptoms of an inflammatory disease. These include:
- Persistent and continuous headache.
- Fever.
- Weight loss in the absence of a dietary regimen.
- Joint stiffness.
- Persistent and constant sore throat.
- Sudden loss of appetite.
- Anemia.
Many other conditions can affect how quickly red blood cells are deposited in a sample.
Therefore, information about inflammatory diseases (what the doctor wants to know from the ESR analysis) can be masked by the influence of other pathologies.
These factors that complicate or affect the accuracy of the test may be, for example: advanced age, pregnancy, kidney problems or thyroid disease.
In any case, it is up to the doctor to interpret and read the results of the analysis of the erythrocyte sedimentation rate.
ESR: what are the normal values
There are a number of reference values obtained from this blood test that help the doctor read and interpret the ESR results, in order to make a correct diagnosis.
The values can vary according to age and gender, in fact, they are slightly higher in women and increase with age. But they can vary from laboratory to laboratory, depending on the method used.
The analysis results are measured in millimeters per hour. The following values are considered normal ESR test results (reference values).
- Women: under 50 should have an ESR of less than 20 mm/h.
- Men: under 50 should have an ESR of less than 15 mm/h.
- Newborns: should have an ESR between 0 and 2 mm/h.
- Children: Those who have not yet reached puberty (0-18 years) should have an ESR between 3 and 13 mm/h or even less than 10 mm/h.
- Normal ESR in the elderly: Women over 50 (between 50 and 85 years) should have an ESR of less than 30 mm/h. Men over 50 (between 50 and 85 years) should have an ESR of less than 20 mm/h.
At the same time, women over the age of 85 should have an ESR of less than 42 mm/h and men over the age of 85 should have an ESR of less than 30 mm/h.
VES alta: cause
If the test reports a result that does not comply with the reference parameters (erythrocyte sedimentation rate too high or too low), it is not possible for the doctor, contrary to what one thinks, to say exactly what is wrong.
However, at the same time, it may indicate the need to investigate further with other diagnostic and laboratory tests.
Some of the conditions commonly associated with an increase in ESR include:
- Anemia.
- Kidney disorders.
- lymphomas.
- Multiple myeloma.
- Old age.
- Pregnancy.
- Thyroid disease.
- Some types of arthritis.
Autoimmune diseases
The values obtained from the analysis of the ESR, when higher than those considered normal, can also be associated with autoimmune diseases, including:
- Systemic lupus erythematosus.
- Rheumatoid arthritis.
- Arteries temporale.
- Polymyalgia rheumatica.
- Macroglobulinemia primaria.
- High blood fibrinogen or hyperfibrinogenemia.
- Allergic vasculitis or necrotizing vasculitis.
Chronic infections
Some types of chronic infections that cause high (higher than normal) ESR values can be:
- Bone or heart infections.
- Rheumatic fever.
- Skin infections.
- Tuberculosis.
- Systemic infections.
High ESR: when to worry?
Among the factors that can influence ESR values, anemia is the main one. The ESR, in fact, is inversely proportional to the presence of red blood cells, so it is high precisely in the case of anemia. The shape and volume of the red blood cells also influence the erythrocyte sedimentation rate, since spherocytes and microcytes (smaller-than-normal red blood cells) sediment more slowly.
High ESR values are also recorded in tissue necrosis (as in cases of trauma), during pregnancy and in some specific diseases in which more antibodies are produced.
It is important not to become too alarmed if the results obtained from the analysis are abnormal (too high or too low).
The best solution remains to talk to your doctor, to understand together what is causing the symptoms you are experiencing and possibly complete the diagnostic picture with an accurate medical history or further specialty investigations.
Also, if your results are outside the normal ESR values, it doesn’t necessarily mean you have a medical problem that requires treatment.
A moderate ESR may indicate pregnancy, menstruation, or moderate anemia, not necessarily an inflammatory disease.
Some medications and dietary supplements can also affect the results of the ESR analysis. These include: oral contraceptives, aspirin and cortisone medications.
So, let’s not forget to inform your doctor of the medications (including supplements) you are taking at that time.
Low ESR: what possible causes?
Low ESR values can be due to several causes, including: young age, increased number of red blood cells (polyglobulia), cold or red blood cells smaller than average (as can occur in microcytosis) and states of malnutrition.
But it can also be an indicator of some diseases, always to be confirmed, let us remember, with further analyses. Among the possible diseases are:
- Congestive heart failure.
- Hypofibrinogenemia (deficiency of the clotting factor fibrinogen and, for this reason, the patient’s tendency to bleed increases).
- Leukocytosis (abnormal increase in white blood cells, often due to dehydration or infection).
- Decreased plasma proteins.
- Polycythemia or “polycythemia vera”, a disease of the cells of the bone marrow, due to an increase in the number of erythrocytes (red blood cells), and therefore to a decrease in blood flow.
- Sickle cell anaemia.
How the exam is performed
ESR is a simple blood test. The sampling is normally performed in the morning (except in cases of urgency) after having observed a period of fasting from the night before.
The whole procedure usually takes no more than a few minutes. A nurse will use a needle to collect a small amount of blood from a vein, usually from the…
