PSA (Prostate-Specific Antigen)
Updated: June 2025
PSA (Prostate-Specific Antigen) is a protein produced by cells of the prostate gland. PSA blood level determination is the primary screening method for prostate cancer and other prostate diseases.
What the Test Measures
- Prostate cancer screening
- Prostate cancer treatment monitoring
- Differential diagnosis of benign hyperplasia vs cancer
- Post-prostatectomy follow-up
Reference Ranges
| Age | Upper Normal Limit |
|---|---|
| 40–49 years | 2.5 ng/mL |
| 50–59 years | 3.5 ng/mL |
| 60–69 years | 4.5 ng/mL |
| 70–79 years | 6.5 ng/mL |
Generally accepted threshold: up to 4 ng/mL. The "gray zone" is 4–10 ng/mL: free PSA and free/total PSA ratio determination is recommended.
Causes of Elevation
- Prostate cancer
- Benign prostatic hyperplasia (BPH)
- Prostatitis (acute and chronic)
- Prostate massage, transrectal ultrasound
- Urinary retention
- Age over 50 (physiological increase)
Test Preparation
- Blood drawn fasting
- Avoid sexual activity 2 days before the test
- Do not test after prostate massage, catheterization, TRUS (wait 7 days)
- Avoid heavy physical activity the day before
When to See a Doctor
If PSA exceeds 4 ng/mL or there's a rapid rise (velocity >0.75 ng/mL/year), consult a urologist for additional evaluation.
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