The PSA Test Explained: What Your Number Means and When to Start Screening

Quick answer: PSA (prostate-specific antigen) is a protein made by the prostate, measured with a simple blood test. Higher levels can signal prostate cancer, but PSA also rises with an enlarged prostate, infection, recent ejaculation, and age. There's no single "normal" number. The American Urological Association recommends offering a baseline PSA to men between 45 and 50, and starting between 40 and 45 for men at higher risk, including Black men and men with a strong family history or known genetic mutations. Regular screening is typically offered every two to four years between 50 and 69.

What does a PSA test measure?

PSA is produced by both normal and cancerous prostate cells. A small amount leaks into the blood. When the prostate is enlarged, inflamed, or affected by cancer, more PSA can reach the bloodstream.

Is there a normal PSA level?

Not a single one. PSA naturally rises with age and prostate size. Urologists look at:

• Your number compared with others your age
• PSA velocity, how fast it's rising over time
• PSA density, PSA relative to prostate size
• Your personal risk factors

A PSA under 4.0 ng/mL was long used as a cutoff, but cancer can occur below it and many men above it don't have cancer. That's why trends and context matter more than one result.

What can raise PSA besides cancer?

• An enlarged prostate (BPH)
• Prostatitis or urinary infection
• Ejaculation within a day or two before the test
• Vigorous cycling
• A recent urinary catheter or procedure

Medications like finasteride and dutasteride lower PSA by about half. Tell every doctor who checks your PSA if you take them.

Who is at higher risk?

• Black men, who have a higher risk of developing and dying from prostate cancer
• Men with a father or brother diagnosed with prostate cancer, especially at a young age
• Men with inherited mutations such as BRCA2
• Increasing age

When should I start screening?

According to the AUA's 2023 early detection guideline:

• Average risk: a baseline PSA between 45 and 50
• Higher risk: start between 40 and 45
• Ages 50 to 69: regular screening every two to four years, personalized to your results

Screening is a shared decision. Your urologist will talk through benefits and tradeoffs.

What if my PSA is high?

Don't panic. The next step is often a repeat test, sometimes followed by an MRI or other tests before a biopsy is considered. Read Elevated PSA: Your Next Steps.