Description

Free and total PSA are two different measurements of prostate-specific antigen (PSA) in the blood, and comparing the two can help determine the risk of prostate cancer:

Free PSA

• Measures the amount of PSA that is not attached to other proteins and is circulating freely in the blood

Total PSA

• Measures the total amount of PSA in the blood, including both the free and bound PSA

Fasting not required.