This test only measures Total PSA. Free PSA is not included.

Free PSA; Total PSA and % Free PSA

PSA (Prostate-Specific Antigen) is a protein produced by the prostate gland. The PSA test measures the level of this protein in the blood and is primarily used to screen for or monitor prostate disorders, including prostate cancer, benign prostatic hyperplasia (BPH), and prostatitis. This test panel includes total PSA, free PSA, and the ratio of free to total PSA (% Free PSA).

1. What Are Free PSA, Total PSA, and % Free PSA?

• Total PSA: The total amount of PSA in the bloodstream (both free and bound to proteins).

• Free PSA: The fraction of PSA not bound to blood proteins, freely circulating in the blood.

• % Free PSA: The ratio of free PSA to total PSA, calculated as: (Free PSA / Total PSA) × 100.

💡 Why measure % Free PSA?
This ratio helps distinguish between benign prostate conditions and prostate cancer, especially when total PSA is moderately elevated (between 4–10 ng/mL).

2. Why Is the PSA Test Panel Done?

This panel is used to:

• Screen for prostate cancer in men, especially those over 50 or at high risk.

• Investigate symptoms such as difficulty urinating, frequent urination, or pelvic pain.

• Monitor men with a history of prostate cancer or elevated PSA levels.

• Determine whether a prostate biopsy is necessary based on PSA results.

3. PSA Test Reference Ranges

• Total PSA:

  - < 4.0 ng/mL: Generally considered normal

  - 4.0 – 10.0 ng/mL: Borderline ('gray zone'); may require % Free PSA analysis

  - > 10.0 ng/mL: Higher likelihood of prostate cancer

• % Free PSA:

  - > 25%: Low risk of prostate cancer

  - 10–25%: Intermediate risk

  - < 10%: High risk of prostate cancer; further evaluation recommended

4. How to Interpret Free PSA, Total PSA, and % Free PSA

🔹 Low Total PSA (< 4.0 ng/mL): Usually no cause for concern, but trends over time matter.

🔹 Moderate PSA (4–10 ng/mL) with High % Free PSA (> 25%): Suggests benign conditions like BPH.

🔹 Moderate PSA (4–10 ng/mL) with Low % Free PSA (< 10%): Suggests a higher chance of prostate cancer; biopsy may be considered.

🔹 High PSA (> 10 ng/mL): High risk of prostate cancer or significant prostate inflammation/enlargement.

5. What Affects PSA Levels?

🔹 Factors that can increase PSA:

• Prostate cancer

• Benign prostatic hyperplasia (BPH)

• Prostatitis (inflammation of the prostate)

• Recent ejaculation or vigorous exercise (e.g., cycling)

• Prostate manipulation (e.g., digital rectal exam, catheterization)

🔹 Factors that can lower PSA:

• Certain medications (e.g., finasteride, dutasteride)

• Obesity

6. When to See a Doctor

🚨 Consult a healthcare provider if you:

• Have an elevated or rising PSA level

• Have a low % Free PSA with borderline total PSA

• Experience urinary symptoms or pelvic pain

• Have a family history of prostate cancer

🔹 Key Takeaways

✅ Total PSA measures all circulating PSA, while Free PSA measures the unbound portion.

✅ % Free PSA helps distinguish between prostate cancer and benign conditions.

✅ A low % Free PSA suggests higher cancer risk and may require further investigation.