What it measures
Platelets are small cell fragments in the blood that clump together to help it clot. The test counts how many are in a litre of blood. It is part of a full blood count.
Why people test it
- Part of a full blood count, used when someone bruises easily or bleeds for longer than expected.
- Monitored on some prescriptions that can lower the count, including some blood thinners and cancer medicines.
- A high count can follow infection, inflammation or low iron, so it is read with the other results.
Typical range
Ranges vary between labs, with the method used, age and sex, and your report shows the lab's own range. One NHS trust lab gives 140 to 400 ×10⁹/L for adults. Source: Gloucestershire Hospitals NHS Foundation Trust: haematology reference ranges.
Finger-prick or vein?
A vein draw is usually advised. Platelets clump in a slow finger-prick sample and small clots form, which can make the count read falsely low.