High Red Cell Distribution Width (RDW): what it means
A Red Cell Distribution Width (RDW) result above the normal range is considered high. Here is what a raised Red Cell Distribution Width (RDW) can point to, and when it is worth discussing with a doctor.
Reference range: 11.5–14.5%
Understand your full resultWhat a high Red Cell Distribution Width (RDW) can mean
- Mixed nutritional deficiency — combined iron + B12/folate; small and large cells together.
- Early iron-deficiency anaemia — RDW often rises BEFORE MCV falls; valuable early signal.
- Recent blood loss or transfusion — fresh young cells alongside older ones.
- Hemolytic anaemia — reticulocytes inflate the size variation.
- Chronic disease, heart failure, CKD — non-specific marker of underlying systemic illness.
When to discuss with a doctor
RDW is part of the diagnostic conversation in any anaemia work-up — not a standalone test to interpret. In a non-anaemic adult, a persistently elevated RDW with no obvious explanation is increasingly seen as a 'check on overall systemic health' marker; Mediora.AI surfaces the trend in the early-warning module. Treatment is driven by the underlying cause, not the RDW itself.
Conditions this can relate to
Keep reading
One value is a snapshot. Upload the full test to see every marker explained together.
Upload your test - freeMediora.AI is informational - interpretation, not a diagnosis. A single out-of-range value is common and often benign; always discuss decisions with your doctor.