MPV
What it measures, and what changes the number.
MPV, mean platelet volume, is the average size of the platelets, the small cell fragments involved in blood clotting. The analyzer measures it at the same time as it counts platelets.
It is read with the platelet count, PDW (how much platelet size varies) and plateletcrit (the share of blood volume taken up by platelets), since size means more when viewed together with number.
Handling matters for this test. Platelets tend to swell in EDTA tubes over the first hours after collection, so the time between the blood draw and analysis can change the value. Results also differ between analyzer brands and measurement methods (impedance versus optical), which makes comparisons across labs less reliable. Some labs do not report MPV when platelets are clumped. It may be printed as Volum plaquetar mig (VPM) or Volumen plaquetario medio (VPM).
Often read alongside: Platelets, PDW, Plateletcrit