Platelet count

Alternative names:

thrombocyte count

Normal values:

150,000 to 400,000/mm3

Note: mm3 = millimeters cubed

What abnormal results mean:

A diminished number of platelets (below the lower limit of normal) is called thrombocytopenia and an elevated number (above the upper limit of normal) is called thrombocytosis.

A decreased numbers of platelets may be associated with:

• cancer chemotherapy
• disseminated intravascular coagulation (DIC)
• hemolytic anemia
• hypersplenism
• idiopathic thrombocytopenic purpura (ITP)
• leukemia
• prosthetic heart valve
• sequela of massive blood transfusion

Increased numbers of platelets may be associated with:

• polycythemia vera
• post-splenectomy syndrome
• primary thrombocytosis
• certain malignancies
• early CML

Additional conditions under which the test may be performed:

• acquired platelet function defect
• acute lymphocytic leukemia
• acute nonlymphocytic leukemia (AML)
• atheroembolic renal disease
• chronic symptomatic HIV infection
• congenital platelet function defects
• deep intracerebral hemorrhage
• eclampsia
• hairy cell leukemia
• hemolytic-uremic syndrome (HUS)
• hemorrhagic stroke
• hypertensive intracerebral hemorrhage
• idiopathic aplastic anemia
• infectious mononucleosis (CMV)
• infectious mononucleosis (EB)
• intracerebral hemorrhage
• lobar intracerebral hemorrhage
• macroglobulinemia of Waldenstrom
• multiple myeloma
• paroxysmal nocturnal hemoglobinuria (PNH)
• pernicious anemia
• placenta abruptio
• pre-eclampsia
• primary myelofibrosis
• primary thrombocythemia
• secondary aplastic anemia
• thrombotic thrombocytopenic purpura
• von Willebrand's disease