Red Cell Distribution Width (RDW) – what do your numbers mean?
Have you had your Red Cell Distribution Width (RDW) level measured and are unsure what the numbers mean? Here's a clear explanation of the normal range, what high or low levels might indicate, and when it makes sense to get tested.
What is the normal range for Red Cell Distribution Width (RDW)?
What is the normal range for Red Cell Distribution Width (RDW)?
The normal range for Red Cell Distribution Width (RDW) is typically between 12-15%, but can vary depending on the laboratory. RDW is measured as a percentage and indicates the variation in the size of red blood cells. In children, values may be higher in the first months of life and then normalize to the adult range. For pregnant women, RDW usually does not change, even though other blood values may vary. Being close to the limit can indicate early anemia or other blood disorders, and it is important to assess RDW along with other blood test parameters such as MCV and hemoglobin.
What does a low level mean?
A low RDW level is rarely clinically significant but can indicate a uniform size of red blood cells. This is typically seen in conditions where there is no active process affecting erythrocyte production. Symptoms are often absent, but if they occur, they may include fatigue or weakness. Causes can be chronic diseases or a stable condition without iron deficiency. Particularly vulnerable groups include patients with chronic conditions. It is recommended to consult a doctor for further assessment if other blood tests also show abnormal values.
What does a high level mean?
A high RDW level can indicate anisocytosis, where red blood cells vary greatly in size. This is often associated with iron deficiency anemia, vitamin B12 or folate deficiency. Symptoms may include fatigue, paleness, and shortness of breath. Causes include nutritional deficiencies, chronic diseases, or hemolytic anemia. It is important to seek medical advice if RDW is elevated, especially if accompanied by other abnormal blood values. A thorough investigation can help identify the underlying cause and ensure correct treatment.
Get your Red Cell Distribution Width (RDW) level tested
At Celto, you can order a blood test for Red Cell Distribution Width (RDW) directly online – no doctor's referral needed and no long waiting times. We have over 34 sample collection centers at public hospitals throughout Denmark, and your samples are analyzed in the same accredited laboratories used by the rest of the healthcare system. You will receive your results directly on sundhed.dk, just like all other blood tests from the public system.
How it works
When you order a blood test from Celto, you choose which markers you want tested – no doctor's referral necessary. After your purchase, you will receive an email with a link to our booking system, where you choose a time and place. The blood sample itself is taken by authorized healthcare professionals and typically takes only a few minutes.
Where you can get tested
Celto has over 34 sample collection centers at public hospitals and clinics across Denmark. You choose the location that suits you best among our partners, and there are typically available appointments within a few days. Find your nearest sample collection center →
How to get your results
Your blood samples are analyzed in the same laboratories used by your own doctor and the rest of the healthcare system, with the exact same quality and tests. You will receive your results directly on sundhed.dk within a few business days, and Celto will also send an easy-to-understand review of your values so you know what the numbers mean.
Order a Red Cell Distribution Width (RDW) blood test here →