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
A PSA test alone doesn’t provide enough information for a 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 another condition.
All men are at risk of prostate cancer, but a few populations are more likely to develop it. These include:
- older men
- Black men
- men with a family history of prostate cancer
Your doctor may recommend a PSA test to screen for early signs of prostate cancer. They 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 prostate.
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
- help decide when to begin treatment, if you’ve been diagnosed with prostate cancer
- monitor your prostate cancer treatment
If your doctor requests that you have a PSA test, make sure that they’re aware of any prescription or over-the counter medications, 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 medication for several days so your results will be more accurate.
PSA levels can also be falsely elevated by certain activities like bike or saddle riding, sexual activity, and recent ejaculation. Some healthcare professionals will recommend abstaining from these activities for a few days prior to getting a PSA test checked.
To withdraw blood from a vein, a healthcare professional 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 a 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.
Drawing blood is considered safe. The healthcare professional 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 enough blood.
Complications from a routine blood draw are uncommon. However, there are some other risks to be aware of. These include risk of:
- fainting
- 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, which creates some controversy around it. Your doctor may then suspect you have prostate cancer and recommend a prostate biopsy when you don’t actually have cancer. However, elevated PSA does not mean you will go directly to biopsy. Many medical professionals use additional blood testing to make a diagnosis.
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 prostate biopsy or prostate surgery
- a urinary tract infection
- prostatitis, or an inflamed prostate
- benign prostatic hyperplasia (BPH), or an enlarged prostate
- recent ejaculation and bike or saddle riding
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:
- digital rectal exam
- free PSA (fPSA) test
- repeated PSA tests
- prostate biopsy
- PHI or 4k score
- prostate MRI
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.
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 cancer.
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.
There’s also no specific level of PSA that’s considered normal for all men. In general, doctors consider a PSA level above 4.0 nanograms per milliliter to be abnormal, according to the
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.
There are several organizations that have issued guidelines for PSA testing. The
- annually for those at high-risk starting at ages 40 to 45
- annually for those at low or average risk starting at 45
- every 2 to 4 years for those at low to average risk between the ages of 55 to 69
- less frequently or not at all starting with age 75
Men between the ages of 70 and 80 and are in otherwise good health should be involved in the decision regarding testing, according to the AUA.
Most organizations agree that high-risk populations should be screened and generally the controversy over PSA screening is not applied to them. In general, though, management of low-risk prostate cancer has become more conservative, usually opting for active surveillance instead of treatment.