PDW puts a number on how widely platelet sizes range around their average. An uneven spread reflects changes in how they are being formed and released. Your doctor checks it along with MPV. Together they help show whether your platelets are being made in an even way.

What is a normal PDW blood test platelet size variation range?

A typical adult range is around 9–17%. No India-specific national reference interval is published for this parameter; your lab's printed range is the most reliable comparison. Ranges vary by lab, method and equipment — the range printed on your own report is the one that applies to your result.

PDW — What It Means in Your Blood Test

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This shows how much your platelets vary in size from one another.

The PDW result helps you understand whether your clotting cells are fairly matched or quite varied in size. Alongside related measures, it gives your doctor a clue about how evenly they are being produced.

Also known as: Platelet Distribution Width, Platelet Dist Width

Kept in balance

This isn't a case where higher or lower is better. Your body keeps it in a narrow band, and both directions can matter.

Last reviewed: 2026-08-16

What is PDW?

PDW puts a number on how widely platelet sizes range around their average. An uneven spread reflects changes in how they are being formed and released.

Why is PDW tested?

Your doctor checks it along with MPV. Together they help show whether your platelets are being made in an even way.

What is a normal PDW range?

India: No India-specific national reference interval is published for this parameter; your lab's printed range is the most reliable comparison.
Global: 9–17%

Ranges vary by lab, method and equipment — the range printed on your own report is the one that applies to your result.

Source: [CLSI, 2010]

What does your PDW value mean?

There is no widely-accepted set of value bands for this parameter. Compare your result with the reference range printed on your own report, and discuss it with your doctor.

What does a high PDW result mean?

A higher-than-usual value means your platelets vary more in size. This can go along with some inflammatory or blood conditions. It is worth discussing with your doctor.

What does a low PDW result mean?

A lower-than-usual value means your platelets are very even in size. This is usually nothing to worry about.

What can affect your PDW result?

How fast platelets are made
Inflammatory conditions
Bone marrow function
Infections
Nutrition

Questions to ask your doctor

About this result

What does my PDW result mean for me specifically, given my age and health?
Is my PDW in the range that is right for me, not just the lab's general range?

What to do next

Could anything I eat, do, or take have affected my PDW result?
Is there anything I should do about my PDW, or is it fine to leave as it is?

About retesting

Does my PDW need to be repeated, and if so, when?
The typical range for PDW can vary between labs — should I compare my result against my own lab's printed range?

The bigger picture

Should my PDW be looked at together with my Hemoglobin and RBC result?
Does my PDW connect to any condition I already have, or to anything I have noticed in how I feel?

Frequently asked questions

What is PDW?: PDW puts a number on how widely platelet sizes range around their average. An uneven spread reflects changes in how they are being formed and released. Your doctor checks it along with MPV. Together they help show whether your platelets are being made in an even way.
What is a normal PDW blood test platelet size variation range?: A typical adult range is around 9–17%. No India-specific national reference interval is published for this parameter; your lab's printed range is the most reliable comparison. Ranges vary by lab, method and equipment — the range printed on your own report is the one that applies to your result.
What does a high PDW result mean?: A higher-than-usual value means your platelets vary more in size. This can go along with some inflammatory or blood conditions. It is worth discussing with your doctor.
What does a low PDW result mean?: A lower-than-usual value means your platelets are very even in size. This is usually nothing to worry about.
What can affect your PDW result?: Several everyday factors can influence it, including How fast platelets are made, Inflammatory conditions, Bone marrow function, Infections, Nutrition.

Sources

CLSI (2010) — Clinical and Laboratory Standards Institute EP28-A3c: Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory

Part of the Complete Blood Count (CBC)

See the full Complete Blood Count (CBC) guide

Related tests in this panel

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