Prostate-Specific Antigen (PSA) Test
The PSA test measures the level of prostate-specific antigen, a protein produced by prostate tissue, in the blood. It is used to assess prostate health and to help evaluate conditions affecting the prostate gland.
What this test evaluates
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PSA concentration in the blood (ng/mL)
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Activity and integrity of prostate tissue
Why a PSA test is ordered
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Screening for prostate cancer risk (age- and risk-dependent)
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Evaluation of urinary symptoms such as frequency, urgency, weak stream, or nocturia
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Monitoring known prostate conditions (benign prostatic hyperplasia, prostatitis)
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Follow-up after prostate cancer treatment or surveillance
How PSA levels are interpreted
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PSA is not cancer-specific
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Elevated levels can be seen with:
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Benign prostatic hyperplasia (BPH)
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Prostatitis or infection
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Recent ejaculation
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Prostate manipulation (exam, catheter, biopsy)
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Aging
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Persistently rising or significantly elevated PSA may warrant further evaluation
Types of PSA testing
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Total PSA: standard screening measure
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Free PSA (percent free PSA): sometimes used when total PSA is borderline to help differentiate benign enlargement from higher-risk patterns
What results may show
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Low or stable PSA: generally reassuring
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Mild elevation: often benign, monitored over time
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Rapid rise or high PSA: may prompt imaging, repeat testing, or urology referral
Specimen requirements
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Blood draw
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Avoid ejaculation and vigorous cycling for 24–48 hours before testing if possible
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Inform the clinician of recent infections, procedures, or medications
Important notes
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PSA trends over time are often more informative than a single value
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Interpretation should consider age, prostate size, symptoms, and medical history
After ordering, you will receive a LabCorp requisition with instructions for blood collection at a participating laboratory.
The PSA test is a useful tool for assessing prostate health but is best interpreted in clinical context rather than as a standalone diagnostic.