Is a PSA Test?
A prostate-specific antigen (PSA)
test measures the level of PSA in a man’s blood. PSA is a protein produced by
the cells of your prostate, a small gland just underneath your bladder. PSA
circulates through your entire body at low levels at all times.
A PSA test is sensitive and can detect higher-than-average levels
of PSA. High levels of PSA may be associated with prostate cancer before any
physical symptoms appear. However, high levels of PSA may also mean you have a
noncancerous condition that’s increasing your PSA levels.
According to the Centers for Disease
Control and Prevention (CDC), prostate cancer is the most common cancer
among men in the United States, other than non-melanoma skin cancer. A PSA test
alone doesn’t provide enough information for your doctor to make a diagnosis.
However, your doctor can take the results of a PSA test into consideration when
trying to decide whether your symptoms and test results are due to cancer or
About the PSA Test
PSA tests are controversial because doctors and experts aren’t
sure if the benefits of early detection outweigh the risks of misdiagnosis.
It’s also not clear if the screening test actually saves lives. Because the
test is very sensitive and can detect increased PSA numbers at low
concentrations, it may detect cancer that’s so small it would never become life-threatening.
Just the same, most primary care physicians and urologists do choose to order
the PSA as a screening test in men over the age of 50.
This is called overdiagnosis.
More men may face complications and risks of side effects from the treatment of
a small growth than they would if their cancer was left undiagnosed. It’s
doubtful those small cancers would ever cause major symptoms and complications
because prostate cancer, in most but not all cases is a very slow-growing
There’s also no specific level of PSA that’s considered normal
for all men. In the past, doctors considered a PSA level of 4.0 nanograms per
milliliter or lower to be normal, reports the National Cancer
Institute (NCI). However, recent research has shown that some men with
lower levels of PSA have prostate cancer and many men with higher levels of PSA
don’t have cancer. Prostatitis, urinary tract infections, certain medications,
and other factors can also cause your PSA levels to fluctuate.
Several organizations, including the U.S.
Preventive Services Task Force, recommend against routine screening with
the PSA test. Speak with your doctor to decide if a PSA test is right for you.
Is a PSA Test Needed?
According to the CDC, prostate cancer
is a leading cause of cancer death in American men. All men are at risk of the
disease, but a few populations are more likely to develop it. These include:
- older men
- African-American men
- men with a family history of prostate cancer
Your doctor may recommend a PSA test to screen for early signs of
prostate cancer. According to the American
Cancer Society, you doctor can also use a digital rectal exam to check for growths.
In this exam, they’ll place a gloved finger into your rectum to feel your
In addition to testing for prostate cancer, your doctor may also
order a PSA test:
- to determine what’s causing a physical
abnormality on your prostate found during a physical exam
- to help decide when to begin treatment, if you’ve
been diagnosed with prostate cancer
- to monitor your prostate cancer treatment
Do I Prepare for a PSA Test?
If your doctor requests that you have a PSA test, make sure that they’re
aware of any prescription or over-the counter medicines, vitamins, or
supplements you take. Certain drugs may cause the test results to be falsely
low. If your doctor thinks your medication might interfere with the results, they
may decide to request a different test or they may ask you to avoid taking your
medicine for several days so your results will be more accurate.
Is a PSA Test Administered?
A sample of your blood will be sent to a laboratory for further
examination. To withdraw blood from an artery or vein, a healthcare provider
will usually insert a needle into the inside of your elbow. You may feel a
sharp, piercing pain or slight sting as the needle is inserted into your vein.
Once they’ve collected enough blood for the sample, they will
remove the needle and hold pressure on the area to stop the bleeding. They’ll then
put an adhesive bandage over the insertion site in case you bleed more.
Your blood sample will be sent to a laboratory for testing and
analysis. Ask your doctor if they’ll follow up with you regarding your results,
or if you should make an appointment to come in and discuss your results.
Are the Risks of a PSA Test?
Drawing blood is considered safe. However, because veins and
arteries vary in size and depth, getting a blood sample isn’t always simple.
The healthcare provider who draws your blood may have to try several veins in
multiple locations on your body before they find one that allows them to get
Drawing blood also has several other risks. These include risk of:
- excessive bleeding
- feeling lightheaded or dizzy
- an infection at the puncture site
- a hematoma, or blood collected under the skin,
at the puncture site
A PSA test can also produce false-positive results. Your doctor
may then suspect you have prostate cancer and recommend a prostate biopsy when
you don’t actually have cancer.
Can I Expect After a PSA Test?
If your PSA levels are elevated, you’ll likely need additional
tests to learn the cause. Other than prostate cancer, possible reasons for a
rise in PSA include:
- a recent insertion of a catheter tube into your
bladder to help drain urine
- recent testing on your bladder or prostate
- a urinary tract infection
- prostatitis, or an inflamed prostate
- an infected prostate
- benign prostatic hyperplasia (BPH), or an
If you have an elevated risk of prostate cancer or your doctor
suspects you may have prostate cancer, a PSA test can be used as part of a
larger group of tests to detect and diagnose prostate cancer. Other tests you
may need include:
- a digital rectal exam
- a free PSA (fPSA) test
- repeated PSA tests
- a prostate biopsy