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Prostate-Specific Antigen (PSA) in Serum by Immunoassay

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

This blood test measures the level of prostate-specific antigen, a protein produced by the prostate gland, often used to screen for or monitor prostate health.

Quick summary

["PSA helps assess prostate health, including potential cancer risk or progression."]

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

Key facts at a glance

LOINC
93398-6
Short code
K oxytoca DNA Bld Pos Ql NAA+probe
Synonyms
K oxytoca DNA Bld Pos Ql NAA+probe
Category
chemistry
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 Is This Test 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 if you’ve already been diagnosed with prostate issues.

What to Expect Before the Test

You’ll have a simple blood draw, usually taken from your arm. Avoid ejaculation or certain medications (like finasteride or dutasteride) for 2 weeks before testing if instructed by your doctor.

What the Results Mean

Results are interpreted based on your age, overall health, and medical history. Higher-than-normal levels may raise concerns, but they don’t always mean cancer. Follow-up tests or discussions with your doctor are needed for clarity.

Common Reasons for Abnormal Results

Elevated PSA can occur with prostate inflammation (prostatitis), benign enlargement, or infection. Lower-than-normal levels might indicate prostate issues like atrophy or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

PSA Test

Frequently asked questions

How long does it take to get PSA test results?
Results are typically available within 1–3 business days, depending on your lab. Your doctor will discuss them with you during your follow-up visit.
Can diet or exercise affect PSA levels?
Dietary changes (like high-fat foods) or strenuous exercise may temporarily alter PSA levels, but they don’t change the test’s diagnostic purpose. Stick to your usual routine unless advised otherwise.
Is a PSA test painful?
The blood draw itself is minimal discomfort, like a pinprick. Most people feel fine afterward. If you’re anxious, ask your doctor about numbing cream or other options.
  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