PSA (prostate-specific antigen) is a protein made by the prostate. A simple blood test measures it and helps detect prostate cancer early, but a raised PSA is not always cancer. Understanding the result avoids both missed cancers and unnecessary worry.
How the test is done
It is an ordinary blood test. For the most reliable result, avoid ejaculation and vigorous cycling for about 48 hours beforehand, and tell your doctor about any recent urine infection, catheter or prostate procedure, which can raise PSA temporarily.
What is a normal PSA?
There is no single cut-off. PSA rises naturally with age and prostate size. As a rough guide, many laboratories use age-related ranges, and levels above about 4 ng/mL usually prompt further assessment, but your urologist interprets the number with your age, prostate size, how fast PSA is changing and examination findings.
Causes of a raised PSA
- Enlarged prostate (BPH)
- Prostate infection or inflammation (prostatitis)
- Recent catheter, cystoscopy or urinary retention
- Prostate cancer
What happens after a high PSA
- Repeat the test, treating any infection first
- Digital rectal examination
- MRI of the prostate to look for suspicious areas
- Targeted biopsy if the MRI or other findings suggest cancer
Who should consider PSA testing?
Men from about 50 (earlier with a family history of prostate cancer) who want to know their risk should discuss PSA testing with a doctor, including its benefits and limits. Read prostate cancer screening tests and prostate cancer surgery.