Complete Blood Count (CBC)

Platelet Count

Also written as: PLT, Thrombocytes

The cells that let blood clot.

What it measures

The number of platelets, the small cell fragments that clump together to stop bleeding.

Why a doctor orders it

Part of every CBC. It is looked at closely before procedures, when unusual bruising or bleeding is reported, and to monitor conditions or medications known to affect clotting.

What is generally associated with a higher result

Broadly associated with inflammation, infection, iron deficiency, recent surgery, removal of the spleen, and less commonly with bone marrow disorders.

What is generally associated with a lower result

Broadly associated with some viral infections, certain medications, autoimmune conditions, liver disease, pregnancy, and bone marrow conditions.

Everyday things that move this number

Not every shift in a value reflects disease. These are ordinary factors known to affect this particular measurement:

  • Recent infection or inflammation
  • Pregnancy
  • Clumping in the tube, which can produce a falsely low result and may need a repeat draw

Questions to take to your appointment

  • Could this be a lab artifact that needs a repeat?
  • Does this change anything about a procedure I have planned?

Build a printable questionnaire with your own results →

Where to read more

MedlinePlus, from the US National Library of Medicine, publishes patient-facing pages on individual lab tests and is a reliable next stop: medlineplus.gov/lab-tests .

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