RDW (red cell distribution width) tests reveal differences in the shape and size of a person's red blood cells. RDW testing can both confirm and help establish the cause of anaemia. RDW is frequently included in the complete blood count (CBC), which determines the number of red and white blood cells, including platelets, in the blood. In this article, we will look into what is the RDW blood test, why this blood test is needed, and how the results will be, so continue reading to know more.
What is the RDW blood test?
The RDW test determines the size and shape difference between a sample's smallest or largest red blood cells. Red blood cells carry air from the lungs to the rest of the body. Haemoglobin, a protein found within cells, binds to oxygen and transports it throughout the body's tissues. Haemoglobin problems can have an impact on the movement that contains oxygen throughout the body, as well as on the shape, size, and function of red blood cells. Red cells in the blood, or erythrocytes, normally have a disc form. However, variances are widespread. If additional cells are smaller or larger than average, RDW test findings may be greater. A high RDW may indicate an underlying health problem.
Why is the RDW blood test taken?
The RDW test can be utilised to aid in the diagnosis of anaemia and other medical problems, such as:
- Thalassemias are genetic blood illnesses that can result in severe anaemia.
- Type 2 diabetes
- cardiovascular disease
- illness of the liver
- cancer
- Symptoms of anaemia include dizziness, pallor, and numbness.
- a vitamin or iron deficit
- a blood ailment, like sickle cell anaemia, in one's family
- severe blood loss as a result of surgery or trauma
- had a diagnosis of a red blood cell disease
- a long-term disease, like HIV or AIDS
When is the RDW blood test needed?
If you suffer from anaemia-like symptoms or a condition connected with anaemia, an RDW blood test can assist your healthcare professional narrow down the diagnosis.
Indicative Symptoms for RDW Test
Your doctor may recommend an RDW blood test to determine whether anaemia is causing the signs and symptoms. The following symptoms characterises anaemia:
- Fatigue.
- Breathing difficulty.
- I'm feeling chilly.
- Feeling faint or dizzy.
- Skin that is pale or dry.
- Headache.
An RDW examination might also reveal the precise type of anaemia you have.
Indicative -Conditions for RDW Test
An RDW blood examination, combined with various RBC indicators, may be utilised to assist in determining what is causing anaemia. Anaemia is linked to the following conditions:
- Cancer
- Cardiovascular illness
- Kidney disease
- The condition of the liver
- Thalassemia
- Chronic ailments (Crohn's disease, diabetes, and HIV)
- Deficiencies in vitamins and minerals (iron, B12, folate)
Anaemia can also be caused by a long-term infection or losing plenty of blood following an injury or surgical operation.
Among the additional red cell indices are
- MCV: A test determining the average diameter of your red blood cells.
- MCH (Mean Corpuscular Haemoglobin): A test determining how much haemoglobin is present in each red blood cell.
- Mean Corpuscular Haemoglobin Levels (MCHC): A test used to assess the amount of haemoglobin present about the size of a red blood cell (Haemoglobin concentration).
A CBC also provides white blood cell and platelet indices. RDW test findings will be examined with other CBC data when a healthcare provider reviews your case.
Other Health Issues
Even if there is no sign of anaemia (when the red blood cell count or haemoglobin levels are normal), the RDW can be a highly useful statistic. Much research has been conducted in recent years to investigate the predictive potential of RDW in various disorders. Some examples are:
1. Heart disease
RDW seems to be a powerful predictor of cardiac failure in persons with heart disease and the chance of acquiring heart disease in people with high blood pressure levels. According to a 2014 study, those with an extremely high RDW (in the highest 5 percent) were 71 percent more likely to suffer a stroke than those with a lower RDW. High RDW may potentially assist in indicating the risk of cardiac disease in HIV-infected individuals.
Also Read: 6 Ways to Lower the Risk of Cardiovascular Disease
2. Cancer
Several studies have been conducted to investigate the role of RDW in cancer. A high RDW may indicate a poor prognosis in numerous types of cancer (including blood-related malignancies, cancer of the lungs, and colon cancer).
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What are the results you get from the RDW blood test?
Test results are displayed as a percentage, indicating whether your findings are within the usual range or your RDW is high or low.
A Normal RDW
A normal outcome means your red blood cells are all the same size. The average RDW is between 12 percent to 15 percent, but this value depends on the laboratory that does the test. Your findings report will emphasise what is regarded as a normal range, allowing you to compare your figures to what is common. A normal result does not indicate that you do not have a problem requiring treatment. Some kinds of anaemia have a normal RDW but a low or high score on one of the additional RBC indices.
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A high RDW
A high RDW indicates more variability in the shape of your red blood cells than is deemed typical. A high RDW may indicate anaemia or a related disease. To be certain, your doctor will need to run more testing. To examine the medical condition with your red blood cells, they'll frequently compare the outcomes from the RDW (variation of red blood cell length) with the results of an MCV (an average of red blood cell size).
Also Read - What Level of RDW is Dangerous in the Blood Test?
A Low RDW
A low level of RDW is rarely a reason for caution and is not linked to any specific kind of anaemia. Because high RDW results can be caused by various circumstances, reducing the fluctuation in red blood cell sizes differs from case to case. Depending on the underlying problem, a doctor may suggest the best way to proceed.
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How to prepare for the RDW blood test?
There is no need to prepare for an RDW test. If the physician has ordered additional blood tests in addition to RDW, someone may be required to fast for many hours before the test. The procedure for drawing blood for the examination is simple and quick. A healthcare expert uses a tiny needle to take blood from the individual's arm. The needle entering the skin may cause a minor scratching or stinging sensation. The needle next injects a little volume of blood into a tube. Once the tube is full, the medical professional removes the tiny needle and may instruct the patient to apply gauze to the collection site to stop blood flow.
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Conclusion
RDW assays assess the size variation between red blood cells within a particular sample. RDW testing can reveal the existence of anaemia and other health issues. It could help in determining the underlying cause. An RDW test is typically performed as a part of a CBC to offer a more complete picture of a person's health.
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