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Prostate-Specific Antigen (PSA) by Immunoassay (Quantitative)

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of prostate-specific antigen (PSA) in your blood. PSA is a protein produced by both healthy and diseased prostate tissue, often used to monitor prostate health or screen for prostate cancer.

Quick summary

["PSA tests help assess prostate health and detect potential issues like cancer or inflammation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
105777-7
Short code
AAC(6')-Ib gene Ct Bld Pos Qn NAA+probe
Synonyms
AAC(6')-Ib gene Ct Bld Pos Qn NAA+probe
Category
glucose
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order a PSA test to check for signs of prostate cancer, especially if you’re at higher risk due to age, family history, or symptoms like urinary changes. It can also help monitor treatment progress or detect early signs of prostate issues.

What to Expect Before the Test

You’ll typically have a simple blood draw from a vein in your arm. Avoid ejaculation for 2–3 days before the test if it’s part of a screening or monitoring plan, as PSA levels can rise after sexual activity.

What the Results Mean

PSA levels vary by age, health, and other factors. Higher-than-normal levels may signal prostate cancer, inflammation, or other conditions, but they don’t always mean cancer is present. Your doctor will discuss results in the context of your medical history.

Common Causes of Abnormal Results

Factors like age, prostate inflammation (prostatitis), infections, or benign prostate enlargement can affect PSA levels. Certain medications or recent medical procedures may also influence results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

PSA is a key marker in prostate cancer screening and diagnosis. While elevated PSA can raise concerns, it’s not definitive on its own. Doctors often use it alongside other tests (like a digital rectal exam or imaging) to guide further evaluation, especially for men at higher risk.

Short name

PSA Blood Test

Frequently asked questions

How long does it take to get PSA test results?
Results are usually available within 1–3 business days, depending on your lab and insurance. Follow-up with your doctor if you have questions about your specific results.
Can PSA levels change over time?
Yes, PSA levels can fluctuate due to factors like age, infections, or recent medical procedures. Regular monitoring may be needed if you have a history of prostate issues or cancer.
Is a PSA test painful?
The blood draw is usually quick and minimally uncomfortable, but you might feel slight soreness or bruising at the site. Most people tolerate it well with minimal discomfort.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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 16, 2026. · Read our editorial policy