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Prostate-Specific Antigen (PSA) Immunoreactive, Serum

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

This test measures the total amount of prostate-specific antigen (PSA) in your blood. PSA is a protein produced by both healthy and diseased prostate tissue.

Quick summary

["PSA levels can help assess prostate health and guide decisions about further testing or treatment."]

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

Key facts at a glance

LOINC
42756-7
Short code
PS IgM B2GP1 indep MoM Ser
Synonyms
PS IgM B2GP1 indep MoM Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 Might Be Ordered

Your healthcare provider may order this test to monitor prostate health, especially if you have symptoms like urinary changes, pain, or a history of prostate issues. It can also be used during screening for prostate cancer or after treatment to check for recurrence.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid ejaculation for 2–4 days before the test if it’s part of a prostate-specific antigen density (PSAD) calculation. Drink plenty of water the day of the test to help your urine flow smoothly.

What the Test Involves

A blood sample will be drawn from a vein, usually in your arm. The process is quick and typically causes only minor discomfort. The sample is sent to a lab for analysis.

What the Results Mean

Results are interpreted based on your age, symptoms, and medical history. Higher-than-normal levels may signal potential prostate issues, but they don’t always mean cancer. Follow-up testing or discussions with your provider are important.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

PSA (Total)

Frequently asked questions

How often will I need this test?
The frequency depends on your health status. Routine PSA screenings are not recommended for all men, but your provider may suggest regular checks if you have risk factors (e.g., family history, age over 50) or symptoms.
What if my PSA level is elevated?
An elevated PSA level can raise concerns, but it doesn’t always indicate cancer. Further tests, like a digital rectal exam or biopsy, may be needed to investigate further. Your provider will discuss next steps with you.
Can diet or medications affect PSA levels?
Certain foods, supplements (like saw palmetto), or medications (e.g., finasteride) may influence PSA levels. Always inform your provider about all medications and supplements you’re taking before the test.
  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