What Is a Prostate-Specific Antigen (PSA) Test?
The PSA blood test measures the concentration of a glycoprotein enzyme produced by cells within the prostate gland. Small amounts of PSA circulate naturally in the bloodstream of all adult men. When the prostate gland experiences cellular irritation, non-malignant expansion (BPH), or acute inflammation (prostatitis), additional PSA escapes into the blood.
Age-Specific NHS Reference Ranges
Under the NHS Prostate Cancer Risk Management Programme (PCRMP), reference ranges are age-stratified because the prostate naturally expands over the decades:
- Men aged 50–59: Normal threshold typically below 3.0 ng/mL.
- Men aged 60–69: Normal threshold typically below 4.0 ng/mL.
- Men aged 70 and over: Normal threshold typically below 5.0 ng/mL.
Crucial Clinical Fact: An elevated PSA is an indicator of prostatic activity or irritation—it is NOT a diagnosis of malignancy. In fact, more than two out of three men with an elevated PSA level turn out to have benign enlargement (BPH) or transient non-malignant prostatitis.
Non-Pathological Factors That Can Elevate PSA
Before undergoing a routine blood draw at your GP surgery, ensure you avoid these common transient triggers that artificially inflate PSA readings for 48 hours:
- Vigorous cycling (due to saddle pressure on the perineum).
- Sexual activity / ejaculation within 48 hours prior to the test.
- Recent urinary tract infections (UTIs) or catheterisation.
- Recent vigorous digital rectal examination (DRE).
Discussing the Test With Your GP
In the UK, any asymptomatic man aged 50 or over has the statutory right to request a PSA blood test free of charge from his NHS GP surgery after receiving balanced clinical counselling on the benefits and limitations of testing.