PDW Platelet Distribution Width
PDW (Platelet Distribution Width) is a parameter reflecting the degree of variability (heterogeneity) in platelet sizes in the blood. It shows how much the platelet volumes vary, helping to assess the uniformity or non-uniformity of the platelet population.
Normal PDW values:
- 9 – 17 %
- Values may slightly differ depending on the laboratory
What PDW indicates:
- High PDW indicates the presence of platelets of varying sizes—this may suggest impaired platelet formation, activation, or destruction.
- Low PDW indicates relative uniformity in platelet size, which is less common.
PDW is increased in:
- Inflammatory diseases
- Iron deficiency anemia
- Oncological diseases
- Ischemic heart disease
- Diabetes
- Bone marrow pathologies
- Thrombocytopathies
PDW is decreased in:
- Suppression of hematopoiesis
- In some forms of aplastic anemia
- Post-chemotherapy or radiation therapy
Clinical significance:
- PDW is used in conjunction with other platelet indices (PLT, MPV, PCT)
- Elevated PDW may indicate an increased risk of thrombosis
- Also used in assessing the effectiveness of treatment for hematological and inflammatory diseases
How the test is performed:
- PDW is automatically calculated as part of a complete blood count
- Blood is drawn fasting, preferably in the morning
Important:
- PDW is an auxiliary parameter and is not used in isolation
- Interpretation requires considering other indicators and the clinical picture