The PSA test is a blood test. PSA (prostate specific antigen) is a protein made by the prostate gland, which naturally leaks out into the blood. The PSA test measures the level of PSA in your blood. Sometimes a raised PSA level can be a sign of prostate cancer. More often it’s caused by something less serious like BPH or prostatitis. A single PSA test can’t show whether a prostate cancer is present, or whether it’s slow or fast-growing.
The level of PSA can also be raised by:
- prostate biopsies (PSA should not be tested until three months after a biopsy)
- having a urinary catheter (a tube to drain urine)
- prostate or bladder surgery (PSA should not be tested until three months after surgery)
- prolonged exercise, such as long-distance running or cycling, which may raise PSA for up to 48 hours
- ejaculation – this may raise PSA for up to 48–72 hours.
Some drugs such as finasteride (Proscar®), which are given to help with urinary symptoms caused by an enlarged prostate gland, can lower the level of PSA in the blood, so this needs to be taken into account. It’s important to tell your healthcare professional (GP or nurse practitioner) about any medicines you are taking before having the test.