What it measures
Fibrinogen is a protein made by the liver. When blood clots, it is turned into strands of fibrin that form the mesh of the clot. The test measures how much is in the plasma, in grams per litre.
Why people test it
- Part of a clotting screen when unexplained bleeding or bruising is being looked into.
- Measured in serious illness to check whether clotting factors are being used up.
- Rises with inflammation, so it is included in some heart and inflammation panels.
Typical range
Ranges vary by lab and method, and levels are naturally higher in pregnancy and in older age. Your report shows the lab's own range.
Finger-prick or vein?
A vein sample is needed. Clotting tests use a special tube that must be filled to an exact level, and blood from a finger prick starts to clot as it is collected.