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Prostate-Specific Antigen (PSA) in Serum/Plasma

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

This test measures the amount of prostate-specific antigen, a protein produced by both healthy and cancerous prostate cells, in your blood.

Quick summary

["PSA helps assess prostate health and detect early signs of prostate cancer or other prostate issues."]

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

Key facts at a glance

LOINC
88267-0
Short code
Proteus sp atpD Bld Pos Ql Probe
Synonyms
Proteus sp atpD Bld Pos Ql Probe
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe
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 This Test Is Done

Doctors may order a PSA test to monitor prostate health, especially if you have symptoms like frequent urination, pain during urination, or an enlarged prostate. It can also be used as part of routine screening for prostate cancer, particularly in men at higher risk.

What to Expect Before the Test

You’ll typically have a small needle inserted into your arm or a blood collection tube placed in your vein. The test is quick and usually done in a doctor’s office or lab. Avoid ejaculation or heavy exercise for 2–3 days before testing if instructed.

What the Results Mean

PSA levels vary by age, health, and other factors. Higher levels may signal prostate cancer, inflammation, infection, or benign prostate enlargement. Your doctor will interpret results in the context of your medical history and symptoms.

Common Causes of Elevated PSA

Elevated PSA can result from prostate cancer, benign prostatic hyperplasia (BPH), prostatitis (inflammation), recent ejaculation, or other conditions like urinary tract infections. It’s not definitive on its own.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

PSA Level Test

Frequently asked questions

What does a PSA test measure?
A PSA test measures the amount of prostate-specific antigen protein in your blood. This protein is produced by prostate cells, and higher levels may signal potential prostate issues, including cancer.
Will I need to fast before this test?
No fasting is required for a PSA test. However, follow any specific instructions your doctor gives you, such as avoiding ejaculation or certain medications, if applicable.
Can PSA levels change with age?
Yes, PSA levels naturally increase with age. Men over 50 are often screened more closely, but results are interpreted based on your overall health, symptoms, and medical history.
  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