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Prostate-specific antigen (PSA) blood test

Prostate-specific antigen; Prostate cancer screening test; PSA

Prostate-specific antigen (PSA) is a protein produced by prostate cells.

The PSA test is done to help screen for and follow prostate cancer in men.

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Blood test

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 not have a PSA test soon after having a urinary tract infection or undergoing a procedure or surgery involving the urinary system. Ask your provider how long you should wait.

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 could potentially 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:

Normal Results

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, but this varies by age:

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.

Risks

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:

Related Information

Prostate cancer
Enlarged prostate
Prostate brachytherapy - discharge

References

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 October 18, 2019. Accessed January 24, 2020.

Small EJ. Prostate cancer. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 191.

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 pubmed.ncbi.nlm.nih.gov/29801017/.

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Review Date: 1/15/2020  

Reviewed By: Sovrin M. Shah, MD, Assistant Professor, Department of Urology, The Icahn School of Medicine at Mount Sinai, New York, NY. Review provided by VeriMed Healthcare Network. Internal review and update on 06/03/2021 by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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