What This Value Measures
PSA is a protein from the prostate that is measurable in the blood. It is used to assess the prostate and in screening.
Elevated Value
An elevated value may indicate benign enlargement, inflammation, or a condition of the prostate.
Low Value
There is no value below which prostate cancer can be ruled out: the risk rises continuously with PSA, without a sharp cut-off. A value of 3.9 is therefore not "normal" and 4.1 is not "abnormal".
Note: Assessment is risk-based: age, how the value changes over time, prostate size, symptoms and further examinations are all taken into account. Cycling, examinations or inflammation can temporarily raise the value; medications for an enlarged prostate (5-alpha-reductase inhibitors) roughly halve it.
Reference ranges are typical guide values for adults and vary depending on the laboratory, measurement method, age and sex — always compare with the range stated on your own report. A value outside the range does not automatically mean an illness, and a value within the range does not rule one out. The trend and overall picture are usually more informative than a single value. The doctor's assessment is always decisive.