All tests › Tumour markers

PSA (free)

Tumour markers · also printed as Free PSA, fPSA, PSA free, Unbound PSA

Typical UK adult rangeNo single typical range

No fixed range; read as a ratio to total PSA.

What this test measures

Free PSA is the fraction of PSA circulating unbound to other proteins. It is only meaningful together with the total value, as the ratio between them.

Why doctors request it

Specialists request it when the total PSA sits in a grey zone.

What commonly pushes it up

The same things that raise total PSA

What commonly pushes it down

The same things that lower total PSA

Everyday reasons for a value outside the range

Meaningless without the total PSA from the same sample

About the sample

Same preparation as total PSA.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.

Got a report with PSA (free) on it?

Upload a photo or PDF and see every line against the range your lab printed, explained in plain English. First report free.

Read my report free

This is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.