What is a PSA test?
PSA (Prostate-Specific Antigen) is a protein produced by both normal and abnormal prostate cells. A small amount of PSA normally leaks into the bloodstream. The PSA test measures this level. Elevated PSA can be caused by prostate cancer, benign prostatic hyperplasia (BPH — non-cancerous enlargement, very common in older men), prostatitis (prostate infection/inflammation), recent prostate exam or biopsy, or ejaculation within 48 hours of the test. PSA alone cannot diagnose cancer — it is a screening flag, not a definitive test.
PSA Normal Range by Age
| Age Group | PSA Upper Limit (ng/mL) |
|---|---|
| 40 – 49 years | < 2.5 |
| 50 – 59 years | < 3.5 |
| 60 – 69 years | < 4.5 |
| 70 – 79 years | < 6.5 |
| General cutoff (most labs) | < 4.0 |
What does HIGH PSA mean?
HIGH PSA above age-adjusted normal
A raised PSA needs to be interpreted carefully. Most men with a PSA between 4–10 ng/mL do NOT have prostate cancer — only about 25% will. Common causes of high PSA: benign prostate enlargement (BPH), prostate infection (prostatitis), recent prostate biopsy or digital rectal exam, recent ejaculation, urinary tract infection. Your doctor will consider your age, symptoms (difficulty urinating, weak stream, frequent urination), PSA velocity (how fast it's rising) and digital rectal exam (DRE) before recommending a biopsy. PSA above 10 ng/mL has a higher cancer probability (~50%) and usually warrants a biopsy.
Free PSA vs Total PSA
Free PSA ratio helps distinguish cancer from BPH
PSA exists in two forms in the blood: free PSA and PSA bound to proteins. The Free PSA % = (Free PSA ÷ Total PSA) × 100. A higher free PSA % suggests BPH (non-cancerous). A lower free PSA % (under 10–15%) suggests higher cancer risk. Doctors use the free PSA ratio to decide whether a biopsy is needed when total PSA is borderline (4–10 ng/mL).
Questions to ask your doctor
- Is my high PSA more likely BPH, prostatitis or cancer based on my symptoms?
- Should I check free PSA ratio?
- Do I need an MRI (mpMRI) of the prostate before considering biopsy?
- How often should I recheck PSA if I'm not having a biopsy?