Prostate-Specific Antigen (PSA)
A prostate-specific antigen (PSA) test measures the amount of
prostate-specific antigen in the blood. PSA is
released into a man's blood by his
prostate gland . Healthy men have low amounts of PSA in
the blood. The amount of PSA in the blood normally increases as a man's
prostate enlarges with age. PSA may increase because
of inflammation of the prostate gland (prostatitis) or
prostate cancer. An injury, a digital rectal exam, or
sexual activity (ejaculation) may also briefly raise PSA levels.
- Prostate Cancer Screening: Should I Have a PSA Test?
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Prostate Cancer Screening: Should I Have a PSA Test?
Why It Is Done
The prostate-specific antigen (PSA) test
is done to:
- Screen men for prostate cancer. Since other common medical
conditions, such as benign prostatic hyperplasia (BPH) and prostatitis, can cause high PSA levels, a prostate
biopsy may be done if your doctor is concerned about signs of prostate cancer.
- Check if cancer may be present when results from other
tests, such as a
digital rectal exam, are not normal. A PSA test does
not diagnose cancer, but it can be used along with other tests to determine if
cancer is present.
- Watch prostate cancer during active surveillance or other treatment. If PSA levels increase, the cancer may be growing or spreading. PSA is
usually not present in a man who has had his prostate gland removed. A PSA
level that rises after prostate removal may mean the cancer has returned or has
How To Prepare
Before you have a prostate-specific
antigen (PSA), tell your doctor if you have had a:
- Test to look at your bladder (cystoscopy) in the past several
- Prostate needle biopsy or prostate surgery in the past several weeks.
- Digital rectal exam in the past several weeks.
- Prostate infection (prostatitis) or an
urinary tract infection (UTI) that has not gone
- Tube (catheter) inserted into your bladder recently to
Do not ejaculate for 24 hours before your PSA blood
test, either during sex or masturbation.
Talk to your doctor about
any concerns you have regarding the need for the test, its risks, how it will
be done, or what the results will mean. To help you understand the importance
of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample
of your blood will:
- Wrap an elastic band around your upper arm to
stop the flow of blood. This makes the veins below the band larger so it is
easier to put a needle into the vein.
- Clean the needle site with
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
- Remove the band from your arm when enough blood is
- Put a gauze pad or cotton ball over the needle site as
the needle is removed.
- Put pressure on the site and then a