Free PSA
Free PSA measures the amount of unbound prostate-specific antigen circulating in the blood. It is used alongside total PSA to help distinguish prostate cancer from benign prostate conditions.
Category: Tumor Markers
Also known as: fpsa, free psa abs, free psa value, psa free value
Reference range: 0–0 ng/mL (Source: ABIM)
Standard unit: ng/mL
High values may indicate
A higher proportion of free PSA relative to total PSA is generally associated with benign prostatic hyperplasia rather than cancer.
Low values may indicate
A lower proportion of free PSA relative to total PSA may indicate a higher risk of prostate cancer, prompting further evaluation such as a biopsy.
Frequently asked questions
- What is a normal Free PSA level?
- A typical reference range for Free PSA is 0–0 ng/mL (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
- What units is Free PSA measured in?
- Free PSA is most commonly reported in ng/mL. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
- Where do Free PSA reference ranges come from?
- BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
- Can I track Free PSA over time?
- Yes. Upload results from any lab and BloodId charts your Free PSA over time against its reference range, so you can see whether the trend is rising, falling, or stable.