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Prostate-Specific Antigen (PSA) in Serum by Immunoassay

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

This test measures the level of prostate-specific antigen (PSA) in your blood, a protein produced by both normal and cancerous prostate cells. It helps doctors assess prostate health, monitor treatment, or detect prostate issues.

Quick summary

["PSA levels can indicate prostate health and guide further medical evaluation."]

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

Key facts at a glance

LOINC
107018-4
Short code
RSV RNA BAL Ql NAA+n-prb
Synonyms
RSV RNA BAL Ql NAA+n-prb
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-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 Is This Test Done?

Your doctor may order this test to check for prostate cancer, monitor symptoms like frequent urination or pain, or evaluate treatment progress. It can also help detect early signs of benign prostate enlargement or inflammation.

What to Expect Before the Test

No special preparation is needed, but avoid ejaculation for 2–3 days before testing if possible. You may have a blood draw in a clinic or lab, and it usually takes a few minutes.

What the Results Mean

Results are interpreted based on your age, symptoms, and medical history. While PSA alone isn’t definitive for cancer, it can signal areas for further testing, such as a biopsy or additional imaging.

Common Causes of Abnormal Results

Elevated PSA may occur with prostate cancer, benign prostate conditions (like BPH), infections, or injuries to the prostate. Lower-than-normal levels might suggest prostate shrinkage or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

PSA Level

Frequently asked questions

How long does it take to get my PSA test results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss them with you during your follow-up visit.
Can diet or medications affect PSA levels?
Certain foods (like cruciferous vegetables) or medications (e.g., finasteride, saw palmetto) may influence PSA levels. Always inform your doctor about all medications or supplements you take.
Is PSA testing painful?
The blood draw is usually quick and minimally uncomfortable, similar to a routine blood test. Most people feel only mild soreness afterward, which can be managed with ice or over-the-counter pain relievers if needed.
  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