All about the prostate-specific antigen check

The prostate-specific antigen (PSA) test is a blood test used to measure levels of PSA; a protein produced by the prostate gland. While some PSA is naturally present in the blood, elevated levels can indicate prostate conditions, including prostate cancer.

The results of a PSA test.

What is the PSA test used for?

The PSA test is primarily used to:

Screen for prostate cancer: Higher PSA levels can suggest the presence of prostate cancer, though further testing is needed for confirmation.
Monitor prostate health: It helps detect benign conditions such as prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate.
Track cancer progression: For individuals diagnosed with prostate cancer, regular PSA checks can assess the effectiveness of treatment and detect recurrence.

What are normal PSA levels?

PSA levels can vary depending on factors such as age and prostate size. While there is no universally defined "normal" level, general guidelines include:

Under 3 ng/mL – Considered low risk for most men under 60
3–4 ng/mL – Requires further evaluation, particularly in men over 60
Above 4 ng/mL – May indicate prostate conditions, but not always cancer

Since other factors can influence PSA levels, a single high reading does not confirm prostate cancer.

What factors can affect PSA levels?

Fluctuations in PSA levels can be caused by several factors. These include:

Age – PSA levels naturally rise with age.
Prostate conditions – BPH and prostatitis can increase PSA.
Recent ejaculation – Can cause temporary PSA elevation.
Medical procedures – A recent prostate examination or catheter use may temporarily raise levels.
Medications – Certain drugs used to treat BPH or urinary issues may lower PSA readings.

When should you get a PSA test?

A PSA test is often recommended for men over 50 or earlier (from age 45) for those with:

A family history of prostate cancer
Black African or Caribbean ancestry, as this group has a higher risk
Symptoms such as frequent urination, difficulty starting or stopping urination, or blood in urine or semen

What happens if PSA levels are high?

If PSA levels are elevated, further tests may be needed, such as:

A repeat PSA test to confirm results
A digital rectal examination (DRE) to assess the prostate’s size and texture
An MRI scan or prostate biopsy to check for cancerous cells

How reliable is the PSA test?

While the PSA test is a valuable tool, it is not definitive. Some men with prostate cancer have normal PSA levels, while others with high PSA do not have cancer. This is why doctors use PSA results alongside other assessments when considering further investigations.

Regular PSA testing, especially for those at higher risk, can help detect prostate cancer early, improving treatment outcomes.