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Prostate-Specific Antigen (PSA) in Serum by Immunoassay (Screening)

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

This test measures the level of prostate-specific antigen (PSA), a protein produced by both healthy and cancerous prostate cells. It helps assess prostate health and detect early signs of prostate cancer or other prostate issues.

Quick summary

["PSA screening may help identify potential prostate problems early, though results alone don’t diagnose cancer."]

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

Key facts at a glance

LOINC
57441-8
Short code
T gondii DNA Fld Ql NAA+probe
Synonyms
T gondii DNA Fld Ql NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order a PSA test to monitor prostate health, especially if you have symptoms like urinary changes, pain, or a family history of prostate cancer. It’s also used during routine check-ups for men over 40 or those at higher risk.

What to Expect Before the Test

No special preparation is needed. You’ll likely have a simple blood draw from a vein in your arm. Avoid ejaculation or prostate massage for 2 days before testing if possible.

What the Results Mean

PSA levels vary by age, health, and other factors. A low result doesn’t always mean no issue, while a high result may prompt further testing. Your doctor will interpret results in the context of your medical history.

Common Causes of Elevated PSA

High PSA can result from prostate inflammation (prostatitis), benign enlargement (BPH), or prostate cancer. Other conditions, like urinary tract infections or recent ejaculation, can also temporarily raise levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

PSA screening is a tool to detect prostate cancer early, but it’s not foolproof. False positives or negatives can occur, so follow-up tests (like a biopsy) may be needed if results are abnormal. Regular monitoring helps track changes over time.

Short name

PSA Screen

Frequently asked questions

Does this test detect prostate cancer directly?
No, PSA alone doesn’t diagnose cancer. It’s a marker that may indicate prostate issues, prompting further evaluation like imaging or a biopsy.
Can lifestyle changes affect PSA levels?
Yes—exercise, diet, and avoiding smoking may influence PSA levels, but results depend on individual health and medical history.
How often should I get a PSA test?
Your doctor will determine frequency based on age, risk factors, and symptoms. Routine screening isn’t recommended for all men; discuss with your healthcare provider.
  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