Prostate-Specific Antigen (PSA) in Serum by Immunoassay
This test measures the level of prostate-specific antigen (PSA), a protein produced by both normal and cancerous prostate cells, in your blood. It helps assess prostate health and detect potential issues like prostate cancer.
["PSA levels can guide discussions about prostate health, but results alone don’t diagnose cancer."]
Key facts at a glance
- LOINC
- 72268-6
- Short code
- S pyogenes speB Spec Ql NAA+probe
- Synonyms
- S pyogenes speB Spec Ql NAA+probe
- Category
- coagulation
- 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
Doctors may order a PSA test to monitor symptoms of prostate problems, such as urinary changes or pain. It’s also used during screenings for prostate cancer, especially in men at higher risk. Regular PSA tests can help track changes over time if you have an existing prostate condition.
What to Expect Before the Test
No special preparation is needed, but you may be asked to avoid ejaculation for 2–4 days before the test. Drink plenty of water to help your urine flow easily. If you’re on certain medications (like blood thinners), let your provider know.
What the Results Mean
PSA levels vary by age, overall health, and medical history. A low level might suggest normal prostate function, while higher levels could signal inflammation, infection, or cancer. Your doctor will interpret results in the context of your health and symptoms.
Possible Side Effects or Risks
The blood draw itself is minor and usually painless. Rarely, there may be mild bruising or soreness at the needle site. If you have a bleeding disorder or take blood-thinning medications, discuss this with your provider before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
PSA Test
Frequently asked questions
PSA is primarily used to screen for prostate cancer, monitor treatment progress, or evaluate symptoms like urinary issues. However, elevated PSA doesn’t always mean cancer—other conditions (like benign prostate enlargement) can also raise levels. Follow-up tests or imaging may be needed if results are abnormal.
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you to discuss the findings, so check with them for a timeline.
You can eat and drink normally before the test. Avoiding ejaculation for 2–4 days is the only specific preparation, as it helps ensure accurate results.
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