Skip to content

Prostate-Specific Antigen (PSA) in Whole Blood by Immunoassay

Published: August 9, 2026Updated: August 17, 2026

This test measures the level of prostate-specific antigen (PSA), a protein produced by both healthy and diseased prostate tissue, to assess potential prostate health concerns.

Quick summary

["PSA levels can help guide discussions about prostate health, especially in men at higher risk for prostate cancer."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
85783-9
Short code
C krusei DNA Bld Pos Ql NAA+n-prb
Synonyms
C krusei DNA Bld Pos Ql NAA+n-prb
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
22
Ref high
198
Critical range
— – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-probe-amp-tar
CPT
82553
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?

Your healthcare provider may order a PSA test to monitor symptoms of prostate issues, screen for prostate cancer, or evaluate changes in prostate health over time. It’s often used alongside other tests or clinical assessments.

What Does PSA Measure?

PSA is a protein made by both healthy and cancerous prostate cells. Elevated levels may suggest prostate inflammation, infection, benign prostatic hyperplasia (BPH), or prostate cancer, though other factors can influence results.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where it’s analyzed using an immunoassay method to detect PSA levels.

What Are Common Results?

Results are reported in nanograms per milliliter (ng/mL). While reference ranges vary by lab, higher-than-normal levels may prompt further evaluation, including additional tests or imaging.

Reference range

Adult males: 22-198 U/L; Females: 22-198 U/LN/A

Specimen: whole-blood

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: PSA Levels and Prostate Health

Short name

PSA Blood Test

Frequently asked questions

What Does a High PSA Level Mean?
A high PSA level can raise concerns about prostate cancer, but it’s not definitive. Other conditions like infection, inflammation, or an enlarged prostate can also affect PSA levels. Your provider will consider your symptoms, medical history, and other test results to interpret results accurately.
What If My PSA Level Is Low?
A low PSA level usually indicates healthy prostate tissue, but it doesn’t rule out prostate cancer entirely. Some men with cancer may have normal PSA levels, so further evaluation may still be needed.
Does Diet or Exercise Affect PSA Levels?
Yes, certain foods (like tomatoes, lycopene-rich foods) or medications (e.g., finasteride) can temporarily affect PSA levels. Avoiding these for a few days before testing may help get a more accurate baseline.
  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 17, 2026. · Read our editorial policy