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Prostate-Specific Antigen (PSA) in Serum, Confirmed by Immunoassay

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

This test measures prostate-specific antigen (PSA), a protein produced by the prostate gland, to help assess prostate health or detect early signs of prostate cancer.

Quick summary

["PSA levels can help guide discussions about prostate health or cancer screening."]

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

Key facts at a glance

LOINC
14230-7
Short code
PR+ cells NFr Tiss ImStn
Synonyms
PR+ cells NFr Tiss ImStn
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-stain
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 this test to monitor symptoms of prostate issues, such as urinary problems or pain, or as part of routine screening for prostate cancer. It can also be used after a biopsy to check for cancer recurrence.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid ejaculation for 2–3 days before the test. Wear comfortable clothing and plan for a short visit to the lab.

How the Test Works

A blood sample is drawn from a vein in your arm. The lab uses an immunoassay to detect and measure PSA levels in your serum.

Possible Results and Next Steps

Results are reported in nanograms per milliliter (ng/mL). While PSA alone isn’t diagnostic for cancer, it can signal abnormalities that may need further evaluation, such as imaging or additional tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: PSA Levels and Prostate Health

Short name

PSA Confirmation

Frequently asked questions

What Does a High PSA Mean?
Elevated PSA levels can indicate prostate inflammation, infection, benign prostatic hyperplasia (BPH), or prostate cancer. However, other conditions (like urinary tract infections or medications) can also affect PSA levels.
What Does a Low PSA Mean?
Low PSA levels are less concerning but may raise questions if you have symptoms of prostate issues. Some men with low PSA have prostate cancer, so further testing may still be needed.
Does This Test Replace Other Screening Methods?
No, PSA testing is one tool among many. Doctors may use it alongside digital rectal exams, imaging, or genetic testing to guide decisions about prostate health.
  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