What does the Platelet Count and Mean Platelet Volume test measure?

Why is Platelet Count and Mean Platelet Volume measured?

Platelet count assessment is foundational to haemostasis and bleeding risk management. Thrombocytopenia (<140–150 ×10³/µL) stratified by severity: mild (100–150 ×10³/µL) — monitor and investigate cause; moderate (50–100 ×10³/µL) — significant surgical bleeding risk; severe (<50 ×10³/µL) — spontaneous mucocutaneous bleeding risk; critical (<20 ×10³/µL) — spontaneous intracranial and visceral haemorrhage risk requiring urgent management. Causes span immune thrombocytopenic purpura (ITP), drug-induced thrombocytopenia, bone marrow failure, microangiopathic haemolytic anaemia (TTP, HUS), hypersplenism, and disseminated intravascular coagulation (DIC). Thrombocytosis (>400 ×10³/µL) — reactive causes (iron deficiency, infection, post-splenectomy, inflammation) are far more common than clonal essential thrombocythaemia; platelet counts persistently above 600–800 ×10³/µL require JAK2 mutation testing and haematology referral. MPV elevation is associated with platelet hyperactivity and increased arterial thrombotic risk — a cardiovascular risk marker gaining clinical traction alongside hs-CRP and NLR.

Reference ranges

Standard reference

Platelets: 140–400 ×10³/µL; MPV: 7.5–12.5 fL # REVIEWER FLAG: Confirm Quest Diagnostics reference ranges for platelet count and MPV — Quest's platelet lower limit may be 140 or 150 ×10³/µL depending on the platform version. Confirm whether MPV is a standard CBC component in Quest's panel or requires separate reporting, and whether Quest's specific platelet critical value threshold is <50 ×10³/µL or <20 ×10³/µL.

Functional medicine optimal

Platelets: 175–350 ×10³/µL (functional medicine cardiovascular optimal — very high platelet counts carry increased thrombotic risk in high-risk cardiovascular patients); MPV: 8.0–11.0 fL. # REVIEWER FLAG: MPV cardiovascular risk optimal is based on emerging literature and is not a standardised clinical guideline target — reviewer to confirm framing.

Units

Platelets: ×10³/µL, MPV: fL

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.