Tumor Markers

PSA (Prostate-Specific Antigen) — What Your Blood Test Result Means

ScanHealth Learn Tumor Markers PSA (Prostate-Specific Antigen)

Your Prostate Health Marker

PSA is a protein produced by prostate cells—ALL prostate cells, not just cancerous ones. It's "prostate-specific," not "cancer-specific." An enlarged prostate (BPH), prostatitis, ejaculation, cycling, and even a digital rectal exam can raise PSA. That said, rising PSA or very high PSA significantly increases the likelihood of prostate cancer and warrants investigation.

What is PSA (Prostate-Specific Antigen)?

PSA is a serine protease produced by prostatic epithelium. It liquefies semen. Normal serum PSA is mostly bound to alpha-1-antichymotrypsin; free PSA is a smaller fraction. Free PSA percentage helps distinguish BPH (higher free %) from cancer (lower free %). PSA velocity (rate of change) and density (PSA/prostate volume) add diagnostic value.

What High PSA (Prostate-Specific Antigen) Means

Something is making your prostate produce more PSA. Could be benign enlargement (BPH, very common after age 50), prostatitis (infection/inflammation), or prostate cancer. PSA >4 ng/mL traditionally triggers further evaluation, but context matters enormously.

Common symptoms:

Often asymptomatic (why screening matters) · BPH symptoms: frequent urination, weak stream, nocturia, incomplete emptying · Advanced cancer: bone pain, weight loss, urinary obstruction

What Low PSA (Prostate-Specific Antigen) Means

Reassuring for prostate cancer risk. Very low PSA (<1 ng/mL) in men over 60 means very low 10-year prostate cancer risk.

Common symptoms:

No symptoms—reassuring

Why It Matters

When normal:

Primary screening tool for prostate cancer

PSA velocity (rising trend) is more informative than single value

Free PSA % helps distinguish BPH from cancer

Very low PSA is very reassuring

Risks if abnormal:

Elevated: could be cancer, BPH, or prostatitis

Overdiagnosis concern: many prostate cancers are indolent

PSA >10: ~50% cancer risk

PSA 4-10 ("gray zone"): ~25% cancer risk

What Can Cause Abnormal Levels?

BPH (Benign Prostatic Hyperplasia)

55% likely

Enlarged prostate produces more PSA. Very common after age 50. BPH elevates PSA 0.3 ng/mL per gram of prostate tissue.

Prostate Cancer

25% likely

Cancer cells produce PSA. Higher PSA and rapid PSA rise increase cancer probability.

Prostatitis

Prostatic inflammation or infection can dramatically elevate PSA (sometimes >20).

Recent Ejaculation

Ejaculation can raise PSA for 24-48 hours. Abstain 48h before testing.

Cycling

Prolonged cycling puts pressure on prostate and can mildly elevate PSA.

Age

PSA naturally increases with age as prostate grows.

What You Can Do

Repeat PSA if elevated (confirm before biopsy)

Impact: Transient elevations are common \u00B7 Timeline: 4-6 weeks

Abstain from ejaculation 48h before test

Impact: Eliminates this confound \u00B7 Timeline: Pre-test

Treat prostatitis if present before repeating PSA

Impact: Infection can dramatically raise PSA \u00B7 Timeline: 4-6 weeks after antibiotics

If lifestyle changes aren't enough:

Free PSA percentage if total PSA 4-10 (gray zone)

Impact: Free PSA >25% favors BPH; <10% favors cancer \u00B7 Timeline: With repeat PSA

Track PSA velocity over time

Impact: PSA rise >0.75 ng/mL/year is concerning \u00B7 Timeline: Annual

Lycopene-rich diet (tomatoes, watermelon)

Impact: Associated with lower prostate cancer risk (observational) \u00B7 Timeline: Ongoing

Recommended retest: Screening: every 1-2 years if PSA <2.5; annually if 2.5-4; repeat in 4-6 weeks if elevated

Related Markers

free_psa testosterone_total creatinine
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your doctor for diagnosis and treatment.

Got your blood test report?

Upload your PDF and understand ALL your markers in 2 minutes. Plain language. Traffic light status. No medical jargon.

Analyze My Report — Free

First report is free. No credit card needed.

Browse all markers