Blood along with its markers is an indicator of good health. By knowing depicts in the blood, one can easily deal with various deficiencies. Red Blood Cell Distribution Width or RDW as it is called, the parameter that is used to measure the variation in the size of the red blood cell. It is also used to measure the variation of the red blood cell volume. Knowing RDW values will help determine any underlying condition and those with high RDW symptoms need to take treatment with immediate effect.
It is also important to note that the red blood cell distribution width is used to measure the size of the total volume of the red blood cells and not the actual size of the cells. As these cells carry oxygen and carbon dioxide to and from the lungs, they can vary in their size.
What Is Red Blood Cell Distribution Width (RDW) Test?
The test of RDW helps to measure the “amount of red blood cell variation”, both in volume and size. Red blood cells play an important role in your well-being as they carry the oxygen from the lungs to all the parts of the body. When there RDW is above or below the normal range, it can cause problems with the functions of the body. This can also affect the transfer of oxygen to various parts of the body. While the range of RDW is known to identify various diseases, analysis of certain diseases can show a normal RDW.
The standard size of the normal red blood cells is 6-8 micrometers. In cases when the red blood cells are larger, the blood test values will be high. This can mean that the person can have anemia or nutrient deficiency or even an unknown health issue.
What Does A High RDW Mean?
If you find out that you have a high RDW it can mostly be due to a nutrient deficiency like deficiency of folate, Vitamin B12 or even iron. In some cases, such results can also be due to Macrocytic Anemia. Macrocytic anemia occurs when our body fails to produce the needed normal red blood cells or the cells that are produced are way beyond normal.
Also, few people can have Microcytic Anemia, where the produced red blood cells are smaller in size when compared to the normal ones. Such conditions have to be well-diagnosed and a CBC is performed where the portions from RDW and MCV tests are compared and the red blood cell volume is measured.
High RDW and a high MCV occur in case of macrocytic anemias and a high RDW low MCVoccur in case of microcytic anemias.
High RDW Symptoms
While some of the diseases with RDW show no symptoms, there are certain symptoms that should be left unattended. Some of the common symptoms associated with high RDW are mentioned below.
- Symptoms related to anemia like numbness, pale skin or dizziness
- Weakness due to the deficiency of vitamins or iron
- There can be a high chance of high RDW if there is a family history of blood disorder like Sickle Cell Anemia.
- This can also occur to blood loss from trauma or as a part of a surgery.
- High RDW is most common when a patient is diagnosed with diseases that directly affect the red blood cells.
- Chronic diseases like AIDS or HIV
What Causes High RDW?
While there can be many reasons for the occurrence of high RDW, the common reason is the low oxygen levels in the patient’s body. This can also occur when you are suffering from a kidney disease or other major health conditions.
Low Levels of Oxygen
When the levels of oxygen are low, the body tends to increase the production of the red blood cells so as to compensate for the health condition causing it. Some of the causes are,
- Heart diseases
- Heart failure
- Hemoglobinopathy – which is a condition that occurs from birth where the oxygen carrying capacity of the red blood cells is reduced.
- Chronic Obstructive Pulmonary Disease (COPD)
- Scarred or Damaged Lungs
- Sleep Apnea
High RDW levels can also be caused due to the use of performance enhancing drugs like anabolic steroids or protein injections. Dehydration can also be another factor that contributes to high RDW. In such a case, the plasma gets decreased and as a result the count of red blood cells increases. This occurs as the blood cells get more concentrated but the actual number of these cells remains the same.
When an RDW normal range is recorded and the patient has been diagnosed with anemia, there is a high possibility that the patient is suffering from thalassemia.
How To Calculate RDW?
RDW is mostly calculated using a mathematical formula which is mentioned below.
“RDW-CV = (Standard deviation of MCV ÷ MCV) × 100”
While many feel that the “width” used in RDW can be misleading at times, it is necessary to note that the measure is for the deviation of the volume of red blood cells and not its diameter.
How To Treat High RDW?
People suffering from high RDW due to anemia can consult their doctor as it is a treatable condition. Also, depending on the test results and the severity of the condition you can be put on vitamin supplements, and some dietary changes can be recommended as well.
It is important to undergo an RDW blood test along with other tests for any blood disorders and a complete diagnosis has to be done before providing the treatment options. In case you are experiencing irregular symptoms before or after your tests and treatment, do contact your doctor immediately.
Medically Reviewed By
Maanasi specializes in health topics including diet and nutrition. A mother of an untiring seven year old, she enjoys nurturing her love affair with English. She is often found nestled with a book, plopped against a dozen pillows, smiling away at the brink of finishing yet another book of the many dozens, that adorn the shelves of her Mini Library!