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Prostate-Specific Antigen (PSA), Serum — Turbidimetric Mass Concentration

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

Measures the amount of prostate-specific antigen (PSA) in a blood sample using a turbidimetric method. It is commonly used to help evaluate prostate health.

Quick summary

["A PSA blood test measures a protein made by the prostate and is used to help assess prostate conditions."]

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

Key facts at a glance

LOINC
110621-0
Short code
PPAA Msmt Ur
Synonyms
PPAA Msmt Ur
Category
liver
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

The prostate-specific antigen (PSA) test measures the concentration of PSA, a protein produced by prostate cells, in serum from a blood sample. This version of the test uses a turbidimetric laboratory method.

Why might I need this test?

PSA testing may be used to evaluate an enlarged prostate, investigate symptoms such as difficulty urinating, and help assess or monitor prostate cancer. Results are interpreted together with your medical history, examination, and other tests.

How is the test performed?

A healthcare professional draws blood from a vein and separates the serum. The laboratory then measures the amount of PSA in the sample using a turbidimetric method, which estimates concentration from the light scatter of the reaction.

How do I prepare for the test?

Special preparation is usually not required, although your clinician may give specific instructions. Tell the healthcare team if you recently had prostate procedures, infections, or symptoms that could affect the PSA result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated PSA may occur with prostate enlargement, benign prostate conditions, prostatitis, or prostate cancer, but an abnormal result does not by itself diagnose cancer. PSA can also rise temporarily after prostate procedures or urinary infection and may vary with age and other factors. Your clinician will interpret the result in context and may recommend repeat testing or additional evaluation when appropriate.

Short name

PSA Test

Frequently asked questions

Does an elevated PSA mean I have prostate cancer?
No. An elevated PSA can result from several prostate conditions, including benign enlargement, infection, inflammation, recent prostate procedures, or cancer. Further evaluation may be needed to determine the cause.
Is fasting required for a PSA test?
PSA testing usually does not require fasting. Follow any specific instructions from your clinician or testing laboratory.
Can medications or recent procedures affect the PSA result?
Yes. Some medications, prostate examinations, biopsies, catheterization, and urinary or prostate infections can temporarily affect PSA levels. Inform your healthcare team about recent events and medications.
  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