Prostate Specific Antigen testing

PSA stands for Prostate Specific Antigen, it is a protein produced and found in high concentrations within the prostate however it is also found in low concentrations in the blood and this can be detected on a blood test.


It usually takes a few days to get the results from the lab. The PSA test result is always interpreted with an examination of the prostate.

PSA is only produced by the prostate, it is not produced anywhere else in the body. If it is found to be elevated then that has to be related to the prostate. 

Play Video

What increases PSA?

PSA can go up because of prostate cancer, but in the majority of patients it is not diagnostic of prostate cancer, it just highlights which men need to go on and have further investigations which is usually an MRI scan and then prostate biopsies. 3 out of 4 men with an elevated PSA do not have prostate cancer. Also men with an elevated PSA may be diagnosed with a Prostate Cancer that is low grade, non-aggressive and not life threatening and therefore doesn’t need treatment.

Does increased PSA mean cancer?

PSA can go up for reasons other than prostate cancer and it is the role of your Urologist to work out why the PSA might be elevated. Other conditions that put the PSA up include prostatitis (infection/inflammation of the prostate), urinary tract infections, urinary retention (inability to pass urine), catheterisation or any operations on the prostate or bladder.

Sometimes activities such as cycling or ejaculation can influence the PSA result.

It also increases with the size of the prostate so commonly men can have a raised PSA just because their prostate has grown in size with age and therefore they don’t need further investigation as their risk of prostate cancer would be very low.

PSA naturally increases with age so the value that your GP will refer does depend on your age.

Age range

PSA value

Age 50 - 59

PSA value > 3

Age 70 +

PSA value > 5

If you have a risk factor for prostate cancer such as family history or race then you may be investigated at a slightly lower level.

Your Urologist will take into account the size of the prostate and how fast the PSA climbs over time when interpreting the result.