Prostate-specific antigen (PSA) blood test
Prostate-specific antigen (PSA) is a protein produced by prostate cells.
The PSA test is done to help diagnose and follow prostate cancer in men.
Prostate-specific antigen; Prostate cancer screening test; PSA
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
Make sure your health care provider knows all the medicines you are taking. Some drugs cause your PSA level to be falsely low.
In most cases, no other special steps are needed to prepare for this test. You should abstain from ejaculation for 3 days prior to the blood test.
How the Test will Feel
You may feel slight pain or a prick when the needle is inserted. Afterward, there may be some throbbing or a slight bruise. These soon go away.
Why the Test is Performed
Reasons for a PSA test:
MORE ABOUT SCREENING FOR PROSTATE CANCER
Measuring the PSA level can increase the chance of finding prostate cancer when it is very early. But there is debate over the value of the PSA test for detecting prostate cancer. No single answer fits all men.
For some men 55 through 69 years old, screening may help reduce the chance of death from prostate cancer. However, for many men, screening and treatment can be harmful instead of beneficial.
Before having the test, talk to your provider about the pros and cons of having a PSA test. Ask about:
Men younger than age 55 have a higher chance of developing prostate cancer and should talk with their provider about PSA screening if they:
The PSA test result cannot diagnose prostate cancer. Only a prostate biopsy can diagnose this cancer.
Your provider will look at your PSA result and consider your age, ethnicity, medicines you are taking, and other things to decide whether your PSA is normal and whether you need more tests.
A normal PSA level is considered to be 4.0 nanograms per milliliter (ng/mL) of blood.
What Abnormal Results Mean
A high PSA level has been linked to an increased chance of having prostate cancer.
PSA testing is an important tool for detecting prostate cancer, but it is not foolproof. Other conditions can cause a rise in PSA, including:
Your provider will consider the following things when deciding on the next step:
Men at high risk may need to have more tests. These may include:
Other tests may also be done. The exact role of these tests in deciding on treatment is unclear.
If you have been treated for prostate cancer, the PSA level can show if treatment is working or if the cancer has come back. Often, PSA level rises before there are any symptoms. This may happen months or years beforehand.
There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another, and from one side of the body to the other. Taking blood from some people may be more difficult than from others. Other risks associated with having blood drawn are slight, but may include:
Morgan TM, Palapattu GS, Partin AW, Wei JT. Prostate cancer tumor markers. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology. 11th ed. Philadelphia, PA: Elsevier; 2016:chap 108.
National Cancer Institute website. Prostate cancer screening (PDQ) - health professional version. www.cancer.gov/types/prostate/hp/prostate-screening-pdq#section/all. Updated February 22, 2018. Accessed June 4, 2018.
US Preventive Services Task Force, Grossman DC, Curry SJ, et al. Screening for prostate cancer: US Preventive Services Task Force recommendation statement. JAMA. 2018;319(18):1901-1913. PMID: 29801017 www.ncbi.nlm.nih.gov/pubmed/29801017.
Review Date: 8/26/2017
Reviewed By: Jennifer Sobol, DO, Urologist with the Michigan Institute of Urology, West Bloomfield, MI. Review provided by VeriMed Healthcare Network. Internal review and update on 11/06/2018 by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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