What it measures
MPV (mean platelet volume) is the average size of the platelets, the cell fragments that help blood clot. It is measured in femtolitres by the same machine that counts the platelets. Larger platelets tend to be younger ones, newly released from the bone marrow.
Why people test it
- Reported with the platelet count in some full blood counts.
- Used with the platelet count when a low or high count is being looked into.
- Can help show whether low platelets are being made too slowly or used up quickly.
Typical range
Ranges vary by lab and analyser, and MPV tends to rise the longer a sample waits before it is tested. Your report shows the lab's own range.
Finger-prick or vein?
A vein sample is usually advised. Blood from a finger prick can clot or break up (haemolyse) in the tube, which upsets blood-count results, and platelets clump easily in capillary samples.