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Prostate-specific antigen (PSA) mass concentration in serum/plasma

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

This test measures the amount of prostate-specific antigen (PSA), a protein produced by both healthy and cancerous prostate cells. It helps assess prostate health and detect early signs of prostate cancer.

Quick summary

["PSA levels can guide decisions about further testing or treatment."]

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

Key facts at a glance

LOINC
19199-9
Short code
PSA Smn-mCnc
Synonyms
PSA Smn-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
4
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84153
SNOMED
39392002
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 a PSA test to monitor symptoms of prostate issues, such as urinary problems, or to screen for prostate cancer, especially if you’re at higher risk. It can also help evaluate treatment progress or detect recurrence after treatment.

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 to get a more accurate result. If you have a recent prostate procedure, your doctor may advise waiting a few weeks.

What Happens During the Test?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab for analysis. The test is quick and typically done in a doctor’s office or clinic.

What Are the Results?

Results are reported as a PSA mass concentration (usually in nanograms per milliliter, ng/mL). While reference ranges vary by lab, higher levels may signal potential concerns, such as prostate inflammation, infection, or cancer.

Reference range

Normal: <4.0 ng/mLN/A

Specimen: serum

No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

PSA levels alone don’t diagnose prostate cancer—they’re part of a broader evaluation. Elevated PSA can indicate prostate issues, but other factors (like age, race, or recent medical procedures) may influence results. Your doctor will interpret results in the context of your health history and symptoms.

Short name

PSA Level

Frequently asked questions

What does a PSA test measure?
A PSA test measures the amount of PSA protein in your blood. PSA is produced by the prostate gland and can be elevated in conditions like prostate cancer, inflammation, or benign enlargement.
How often should I get a PSA test?
The frequency depends on your age, symptoms, and risk factors. The U.S. Preventive Services Task Force recommends against routine PSA screening for men without symptoms, but your doctor may suggest testing if you have risk factors (e.g., family history of prostate cancer) or symptoms like frequent urination.
Can diet or medications affect PSA levels?
Yes, certain foods (like cruciferous vegetables) or medications (e.g., finasteride or dutasteride) may influence PSA levels. Avoiding ejaculation for 2–4 days before testing can help stabilize results.
  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