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Prostate-Specific Antigen (PSA) in Serum by Immunoassay (TMB-based)

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

This test measures the level of prostate-specific antigen (PSA), a protein produced mainly by the prostate gland. It helps assess prostate health, often used in screening for prostate cancer or monitoring prostate conditions.

Quick summary

["PSA tests help detect potential prostate issues, including cancer, early in some cases."]

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

Key facts at a glance

LOINC
86237-5
Short code
N men sg w135 synG Ct Spec Qn NAA+probe
Synonyms
N men sg w135 synG Ct Spec Qn 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

Your doctor may order a PSA test to check for signs of prostate problems, such as inflammation, infection, or cancer. It’s sometimes used as part of routine screening, especially for men at higher risk. Results can also help guide treatment decisions if you already have prostate issues.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid ejaculation for 2–4 days before testing. If you have recent prostate procedures, your doctor may advise waiting a few weeks. Bring any medications you’re taking, as some can affect PSA levels.

What the Test Results Mean

PSA levels vary by age, overall health, and other factors. A higher-than-normal PSA may signal prostate concerns, but it doesn’t always mean cancer. Your doctor will interpret results in the context of your medical history and symptoms.

Possible Causes of Abnormal Results

High PSA levels can be caused by benign conditions like benign prostatic hyperplasia (BPH), infections, or inflammation. Low PSA levels may occur with prostate shrinkage or certain medications. Always discuss results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

PSA Serum Test

Frequently asked questions

How often will I need this test?
The frequency depends on your age, symptoms, and risk factors. Younger men may get tested less often, while those with a family history of prostate cancer or symptoms might be tested more regularly. Your doctor will tailor recommendations to your needs.
Can diet or exercise affect PSA levels?
Dietary factors like high-fat foods or certain supplements may slightly influence PSA, but the effect is usually small. Regular physical activity generally supports prostate health, but it doesn’t change PSA levels meaningfully.
What if my PSA test is abnormal?
If your PSA is elevated, your doctor may recommend further testing, such as a digital rectal exam, ultrasound, or additional PSA subtypes. They’ll work with you to determine the best next steps based on your situation.
  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