Prostate-Specific Antigen (PSA) by Serum Immunoassay (Confirmatory)
This test measures the level of prostate-specific antigen (PSA) in your blood, a protein produced by both healthy and cancerous prostate cells. It helps doctors assess prostate health, monitor treatment, or detect prostate issues like cancer.
["PSA levels can guide discussions about prostate health, but they’re not definitive on their own."]
Key facts at a glance
- LOINC
- 107424-4
- Short code
- XR Penis Views
- Synonyms
- XR Penis Views
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- xr
- 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 Might Be Ordered
Your doctor may recommend this test if you have symptoms like urinary changes, pain in the pelvic area, or if you’re at higher risk for prostate cancer (e.g., age 50+ for men at average risk, or earlier for those with family history). It may also be used during routine check-ups or after prostate procedures.
What to Expect Before the Test
No special preparation is needed, but avoid ejaculation for 2–4 days before testing if instructed by your doctor. Drink plenty of water to help your blood flow smoothly. Wear comfortable clothing and plan to stay near a bathroom for a short blood draw.
What Happens During the Test
A healthcare provider will insert a small needle into a vein in your arm. You may feel a slight pinch, but it’s over quickly. Blood is collected in a tube, and the sample is sent to a lab for analysis. The test usually takes less than 10 minutes.
What the Results Mean
Results are reported in nanograms per milliliter (ng/mL). While PSA levels can vary widely, they’re not the only factor doctors consider. Higher levels may signal prostate issues, but they can also be influenced by age, race, recent ejaculation, or other health conditions. Your doctor will interpret results in the context of your overall health and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
PSA Confirm
Frequently asked questions
How often will I need this test?
Can PSA levels change with age?
What if my PSA level is high?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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