How to Measure Free PSA Count

Free prostate-specific antigen or PSA is a protein that is not attached to other proteins in the bloodstream. Most PSA tests that are performed by doctors measure both free PSA and bound PSA. Researchers believe that men with prostate cancer have more bound PSA than free PSA. The U.S. Food and Drug Administration (FDA) approved the use of PSA screening and a digital rectal exam in men 50 years or older to help detect prostate cancer. A blood test is used to measure free PSA count.

Instructions

• 1

  Schedule an appointment with your medical provider. A PSA count can only be ordered by a doctor.

• 2

  Speak to your physician about your need for a free PSA count. Provide your reasons for the measure and schedule a blood test.

• 3

  Inform your doctor of any medication you are taking. Follow medical instructions prior to the test to ensure the best results. Avoid having sexual intercourse the day before the test.

• 4

  Show up at the laboratory or clinic the day of your test. The nurse will take a sample of blood from your forearm to measure your free PSA count.

• 5

  Review the results with your medical provider. The exact normal and abnormal levels of PSA will vary depending on a variety of factors. Men with low levels of free PSA have a greater risk of developing prostate cancer. To determine if you have a low level of free PSA, take the value reported for your free PSA and divide it by the total value. If the percentage is greater than 25 percent, you have a low risk of developing prostate cancer. If the percentage is lower than 10 percent, the chance of having or developing prostate cancer is high. For percentages between 10 and 25 percent, the risk is not known.