PSA, Total (Prostate-Specific Antigen, Total) Test
The total PSA test measures prostate-specific antigen, the principal biochemical marker for prostate cancer detection, risk assessment, and monitoring. PSA is tissue-specific but not cancer-specific, rising also with benign prostatic hyperplasia, prostatitis, and recent prostatic activity, so it is interpreted against age-specific thresholds and refined with the free-to-total ratio, PSA density,…
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Biomarkers
Blood (serum)
Sample
1–3 business days
Turnaround
No — however, the sample should be taken before, or appropriately after, ejaculation, digital rectal examination, or prostatic instrumentation, which transiently raise PSA
Fasting
What is the PSA, Total test?
The PSA, Total Test measures prostate-specific antigen, the principal biochemical marker used in the detection, risk assessment, and monitoring of prostate cancer. It is ordered to investigate urinary or prostatic symptoms, to inform shared decisions about prostate cancer screening, and to monitor men after a prostate cancer diagnosis or treatment. Within prostate assessment, PSA is tissue-specific but not cancer-specific, so it sits within a broader diagnostic pathway rather than being diagnostic alone. An elevated total PSA prompts consideration of age-specific thresholds, the free-to-total PSA ratio, PSA density and velocity, MRI, and biopsy, while benign causes — benign prostatic hyperplasia, prostatitis, recent ejaculation, catheterisation, or prostatic examination — must be excluded or accounted for. Screening with PSA is a shared decision because of the trade-off between earlier cancer detection and the harms of overdiagnosis. After definitive treatment, PSA is the key marker of residual or recurrent disease, where serial trends matter more than a single value.
What does the PSA, Total test measure?
Prostate-specific antigen is a serine protease (kallikrein-3) produced almost exclusively by prostatic epithelial cells, with the physiological role of liquefying seminal fluid. It circulates in free and protein-complexed forms, the sum of which is the total PSA. Although highly tissue-specific to the prostate, PSA is not cancer-specific: it rises with benign prostatic hyperplasia, prostatitis, prostatic manipulation, and age, as well as with malignancy. PSA has a serum half-life of around 2–3 days.
Total PSA is the principal biochemical marker for prostate cancer detection, risk assessment, and monitoring, and is used to guide decisions about further investigation such as MRI and biopsy. It is tissue-specific but not cancer-specific, so elevations require interpretation against age, prostate size, urinary symptoms, and recent prostatic activity. The free-to-total PSA ratio, PSA density, and velocity refine its specificity, and PSA is central to monitoring response after treatment for prostate cancer.
Why is the PSA, Total test ordered?
- Shared-decision prostate cancer screening in men of appropriate age and risk, after discussion of the benefits and harms
- Investigation of lower urinary tract symptoms or an abnormal prostate on examination, alongside clinical assessment
- Risk assessment in men with a family history of prostate cancer or other elevated-risk features
- Refinement of an elevated PSA using the free-to-total ratio, PSA density, or velocity to inform biopsy decisions
- Monitoring for residual or recurrent disease after prostatectomy, radiotherapy, or other definitive treatment, where serial trends are key
- Surveillance of men on active monitoring for low-risk prostate cancer
- Assessment of treatment response in men receiving therapy for prostate cancer
Sample collection and turnaround
Sample type
Blood (serum)
Fasting required
No — however, the sample should be taken before, or appropriately after, ejaculation, digital rectal examination, or prostatic instrumentation, which transiently raise PSA
Collection method
Venipuncture at patient service centre
Turnaround
1–3 business days
Collection notes
Avoid sampling soon after ejaculation, digital rectal examination, catheterisation, or prostate biopsy, and defer testing during or shortly after a urinary or prostatic infection. Document 5-alpha reductase inhibitor use, and use the same assay for serial monitoring. Advise patients to withhold high-dose biotin for 48–72 hours prior to collection.
Specimen requirements
Minimum 0.5 mL serum. Separate serum from cells per Access Medical Laboratories protocol. Specimen stable refrigerated; follow Access Medical Laboratories transport guidelines.
What can affect PSA, Total results?
PSA rises with prostate volume and age, so benign enlargement raises total PSA without malignancy, which is why age-specific thresholds and PSA density are used.
Inflammation or infection of the prostate can markedly raise PSA; testing is best deferred until the infection has resolved, often several weeks, to avoid a misleading elevation.
Ejaculation, digital rectal examination, catheterisation, cystoscopy, and biopsy transiently raise PSA. Samples should be taken before, or appropriately after, such activity to avoid spurious elevation.
These drugs roughly halve PSA over months, so values in treated men should be doubled (or interpreted against a treatment-adjusted baseline) to avoid falsely reassuring results.
PSA assays differ in calibration, so serial monitoring should use the same assay, and results are interpreted against the performing laboratory's method.
Biotin can interfere with streptavidin-biotin immunoassay platforms, producing falsely altered PSA. Patients should withhold high-dose biotin for 48–72 hours before collection.
What do PSA, Total results mean?
Elevated
An elevated total PSA raises the possibility of prostate cancer but is non-specific, also occurring with benign prostatic hyperplasia, prostatitis, and recent prostatic activity. Benign causes should be excluded or allowed to resolve, and elevation is refined with age-specific thresholds, the free-to-total ratio, PSA density and velocity, and MRI to guide biopsy decisions.
Normal
A PSA within the age-appropriate range, with no concerning clinical findings, suggests a lower likelihood of clinically significant prostate cancer but is not a guarantee of its absence. Serial trends and the overall clinical picture remain important.
Reduced
A low PSA is reassuring but does not entirely exclude prostate cancer, since some cancers produce little PSA. In men on 5-alpha reductase inhibitors, a low value must be interpreted against the treatment-adjusted baseline rather than taken at face value.
Note: PSA is tissue-specific but not cancer-specific, so a single value cannot diagnose or exclude prostate cancer. It is affected by age, prostate size, infection, recent prostatic activity, and 5-alpha reductase inhibitors, and assays differ, so serial monitoring should use the same method. PSA is best interpreted within a structured pathway with age-specific thresholds, derived indices, imaging, and the clinical context, and screening involves a shared decision about benefits and harms.
Frequently asked questions
It measures prostate-specific antigen, a protein produced by the prostate. PSA is the principal biochemical marker used in prostate cancer detection, risk assessment, and monitoring, interpreted within a structured diagnostic pathway.
How to access the PSA, Total test
The PSA, Total reference page is free and open to all practitioners. Create a free practitioner account to see pricing, save tests to your list, and generate requisition forms. Verification takes 1–2 business days.
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Published: June 2, 2026
Last reviewed: June 2, 2026
- US Preventive Services Task Force. Screening for Prostate Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. (2018)
- Schröder FH, et al. Screening and Prostate Cancer Mortality: results of the ERSPC at 13 years of follow-up. Lancet. (2014)
- Catalona WJ, et al. Use of the percentage of free PSA to enhance differentiation of prostate cancer from benign prostatic disease. JAMA. (1998)
- Mottet N, et al. EAU-EANM-ESTRO-ESUR-SIOG Guidelines on Prostate Cancer. Eur Urol. (2021)
This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.
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