Platelet Size Variation
Just like RDW measures variation in red cell size, PDW measures variation in platelet size. Higher PDW means you have a mix of big and small platelets—often a sign that production and consumption are both happening actively.
What is Platelet Distribution Width?
PDW measures the coefficient of variation in platelet volume. It's most useful alongside MPV and platelet count to understand what's happening with platelet production and destruction.
↑ What High Platelet Distribution Width Means
Your platelets vary a lot in size. This suggests active turnover—new large platelets being produced while old small ones are still circulating.
Common symptoms:
Not directly symptomatic—reflects underlying condition
↓ What Low Platelet Distribution Width Means
Platelets are uniformly sized. Generally not clinically concerning.
Common symptoms:
Not directly symptomatic
Why It Matters
When normal:
Helps distinguish reactive from pathological platelet changes
Indicator of bone marrow response
Emerging sepsis and inflammation marker
Risks if abnormal:
High PDW: active platelet turnover, immune destruction, sepsis
Abnormal PDW warrants investigation when paired with other abnormalities
What Can Cause Abnormal Levels?
Immune Thrombocytopenia
45% likelyImmune destruction triggers rapid new production, creating size diversity.
Sepsis or Severe Infection
40% likelyPDW rises in sepsis and is being studied as an early marker.
B12 or Folate Deficiency
Nutritional deficiencies affect platelet maturation consistency.
What You Can Do
Balanced nutrition with adequate B12 and folate
Impact: Supports consistent platelet production \u00B7 Timeline: 4-8 weeks
If lifestyle changes aren't enough:
Address underlying inflammation or infection
Impact: Normalizes platelet dynamics \u00B7 Timeline: Varies
Recommended retest: 3 months
Related Markers
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