Prostate-specific antigen (PSA) test

A prostate specific antigen (PSA) test is a blood test that measures the PSA level in a sample of your blood. PSA is a protein that is produced by your prostate. The prostate is a gland in the male reproductive system. It is located just below the bladder. It produces the liquid part of sperm.

It's normal to have a low PSA level in your blood. A high PSA level can be caused by:

• Prostate cancer
• An enlarged prostate (BPH) (benign prostatic hyperplasia)
• Other Common Prostate Problems
• Taking certain medications

A PSA test cannot show what is causing abnormal PSA levels. So if your level is high, you may need more tests.

Other names: PSA total, PSA free

A PSA test is used to screen for prostate cancer. Cancer screening means looking for signs of cancer before it causes symptoms. But screening tests can't diagnose cancer. If a screening test finds signs of cancer, you'll need more tests to find out if you have cancer and how serious it can be.

Most types of prostate cancer develop very slowly. They don't spread beyond the prostate and may never cause health problems. In fact, you can live a long time with prostate cancer and never know you have it. The goal of prostate cancer screening is to help find cancers that may be more likely to spread so they can be treated early. But there are challenges and possible risks associated with using a PSA test to screen for prostate cancer:

• A PSA test cannot tell the difference between abnormal PSA levels due to prostate cancer and non-cancerous conditions. If your PSA level is high, a prostate biopsy is the only way to find out if the cause is cancer. And prostate biopsies come with possible risks.
• A PSA test can lead to the discovery and treatment of prostate cancer that would never have affected your health. If prostate cancer is found:
  • It can be difficult to tell the difference between slow-growing cancers and cancers that are likely to grow more quickly and spread throughout your body.
  • You may get treatment for prostate cancer that you never really needed. And cancer treatment can cause serious harm, such as:
    • Erectile dysfunction
    • Urinary incontinence
    • Problems controlling your bowels (poop)

To decide if a PSA test for prostate cancer is right for you, talk to your health care provider about:

• Your risk of developing a serious type of prostate cancer If your risk is high, the possible benefits of detecting cancer early may outweigh the possible risks.
• Your overall health. Are you healthy enough to receive treatment for prostate cancer if found?
• Your preferences. What do you think of the potential benefits and risks of screening, diagnosis, and treatment?

PSA tests can also be used to:

• Help diagnose the cause of prostate conditions that are not cancerous
• Monitoring the treatment of a prostate condition, including cancer

It is your choice to have a PSA test for cancer. You and your health care provider can consider your risk of developing a serious cancer that could spread if you don't catch it early. Your risk of serious prostate cancer may be higher based on:

• Age. The risk of prostate cancer increases after age 50.
• Your family health history If members of your family have had prostate cancer, your risk may be higher.
• Your race. Prostate cancer is more common among African Americans. They also have a higher risk of developing prostate cancer at a younger age and of having a more serious condition.

You can also take a PSA test if:

• You have symptoms of a prostate condition, such as:
  • Painful or frequent urination (peeing)
  • Blood in the urine or sperm
  • Pelvic and/or back pain
• You have prostate cancer. Your provider may use the PSA test to monitor your condition or to see how well the treatment is working.

You should avoid having sex or masturbating for 24 hours prior to your PSA test. This is because ejaculation can increase your PSA levels, which can make your results less accurate. Also, some medications may affect your test results, so tell your doctor about all medications you are taking.

There is very little risk in taking a blood test. You may feel a slight pain or bruise where the needle was inserted, but most symptoms go away quickly.

There is no specific normal or abnormal level for PSA in the blood. In general, the higher your PSA level, the more likely it is that you will have cancer. But it is possible to have a high PSA without prostate cancer, or a low PSA with prostate cancer.

If you have had a PSA test for prostate cancer or because you have prostate symptoms:

• High PSA levels may mean that you have prostate cancer or a prostate condition that is not cancer, such as an infection (prostatitis) or an enlarged prostate. If your PSA levels are higher than normal, your doctor may discuss with you the need for further tests to diagnose the cause. These tests may include:
  • Another PSA test, more commonly if you Don't have of symptoms. PSA levels can fluctuate, so it's helpful to see if your PSA levels change over time.
  • A digital rectal examination (ERD). For this test, your doctor inserts a gloved, lubricated finger into your rectum to examine your prostate for lumps or anything unusual.
  • A urine test. A sample of your urine is tested for infection.
  • A prostate biopsy. A biopsy is a minor surgery. A doctor takes tissue samples from your prostate so they can be studied under a microscope to look for cancer cells. A biopsy is the only way to diagnose cancer. It may be recommended if your doctor thinks you may have prostate cancer.

If you have had a PSA test to monitor prostate cancer or treatment, ask your doctor what a high PSA level means. Your doctor will usually review multiple test results over time to get a more complete understanding of your condition.

If you have questions about your results, talk to your doctor.

Learn more about lab tests, reference ranges, and understanding results.

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