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Prostate-Specific Antigen (PSA)

Published: July 21, 2026Updated: August 25, 2026

PSA is a protein produced by the prostate gland, and its levels in the blood can indicate prostate health issues, including cancer.

Quick summary

PSA is a blood test marker used for prostate cancer screening.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
ng/mL
Clinical utility
screening
Result kind
quantitative
FDA-cleared
Roche PSA, Abbott PSA, Siemens PSA, Beckman PSA
interpretation: {"text":"PSA levels below 4 ng/mL are generally considered normal, though this can vary by age and individual risk factors.","label":"Normal"}; {"text":"PSA levels above 4 ng/mL may indicate the need for further testing to rule out prostate cancer or other conditions.","label":"Elevated"}

Prostate-Specific Antigen (PSA) is a protein produced by the prostate gland cells. Elevated levels of PSA in the blood can be a sign of prostate cancer, but they can also indicate other prostate conditions such as prostatitis or benign prostatic hyperplasia (BPH).

PSA screening is commonly used to detect prostate cancer in its early stages, which can lead to more effective treatment. However, it is not a definitive diagnostic tool, as elevated PSA levels can be caused by various factors. Further testing, such as a prostate biopsy, is often required for a definitive diagnosis.

The utility of PSA screening is a subject of ongoing debate due to the potential for false positives and overdiagnosis. Clinical guidelines on PSA testing vary, and decisions about screening should be made in consultation with a healthcare provider, considering individual risk factors and preferences.

Frequently asked questions

What factors can affect PSA levels?
Factors such as age, prostate size, infection, and recent ejaculation can affect PSA levels.
Is PSA screening recommended for all men?
PSA screening is not universally recommended and should be discussed with a healthcare provider based on individual risk factors and preferences.
  1. 1
    American Cancer Society: Prostate Cancer ScreeningSource
  2. 2
    National Cancer Institute: Prostate-Specific Antigen (PSA) TestSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy