What Is PSA? What the Prostate-Specific Antigen Blood Test Measures
PSA stands for prostate-specific antigen. It is a protein enzyme produced mainly by glandular cells of the prostate. Most PSA is released into prostatic fluid and semen, where it participates in semen liquefaction. A much smaller amount enters the bloodstream. A PSA blood test measures that circulating concentration and uses it as a marker of […]
What Is a Normal PSA Level? Age, Prostate Size and Clinical Context
A “normal PSA level” is not one fixed number that applies to every man. PSA varies with age, prostate size, benign prostate growth, inflammation, medications and natural biological variation. A value can therefore be within an expected range for one clinical situation while deserving closer assessment in another. Direct answer There is no single universally […]
PSA Levels by Age: Age-Specific Reference Ranges and Interpretation
PSA levels tend to rise with age, partly because the prostate commonly enlarges over time. This has led to age-specific PSA reference ranges, but they should not be interpreted as fixed boundaries between a healthy prostate and prostate cancer. Age is only one part of PSA interpretation alongside prostate size, previous PSA results, medicines, family […]
What Causes a High PSA? BPH, Prostatitis, Procedures and Prostate Cancer
A high PSA means that more prostate-specific antigen than expected has been measured in the blood for that clinical setting. It does not identify the cause. Benign prostate enlargement, inflammation or infection, urinary retention, recent prostate procedures, normal biological variation and prostate cancer can all contribute to an elevated result. Direct answer The main causes […]
Can PSA Be High Without Prostate Cancer? Benign Causes of an Elevated PSA
Yes. A PSA blood test can be elevated even when prostate cancer is not present. PSA is produced by both normal and abnormal prostate tissue, so benign prostate enlargement, inflammation, infection, urinary retention, recent prostate procedures and normal biological variation can all raise the measured concentration. Direct answer A high PSA does not mean that […]
What Does a Low PSA Mean? Interpretation and Limits of Low Prostate-Specific Antigen
A low PSA generally means that a relatively small amount of prostate-specific antigen is circulating in the blood. In an untreated man undergoing prostate screening, a lower baseline PSA is usually associated with a lower long-term risk of clinically significant prostate cancer. It does not mean that the prostate produces no PSA, that prostate disease […]
What Is Free PSA? How Free and Total PSA Differ
A standard PSA blood test measures several circulating forms of prostate-specific antigen together. Free PSA is the portion circulating without being bound to certain blood proteins. Measuring free PSA alongside total PSA can provide additional information when the total PSA alone cannot clearly distinguish benign prostate conditions from prostate-cancer risk. Direct answer Free PSA is […]
What Is Percent-Free PSA? Free-to-Total PSA Ratio and Cancer Risk Assessment
Percent-free PSA describes how much of the prostate-specific antigen circulating in blood is in the free, unbound form rather than being included only as part of the total PSA concentration. The ratio can help refine prostate-cancer risk when the total PSA result alone leaves uncertainty, particularly in an intermediate PSA range. Direct answer Percent-free PSA […]
What Is PSA Density? PSA Adjusted for Prostate Volume
PSA density is a calculation that divides the PSA level in the blood by the volume of the prostate. It shows how much PSA is present relative to the amount of prostate tissue. This helps distinguish a PSA that may be partly explained by a large benign prostate from the same PSA occurring in a […]
What Is PSA Doubling Time? Measuring PSA Growth After Prostate Cancer Treatment
PSA doubling time is the estimated time it takes a rising PSA level to double. It is usually reported in months and is used mainly after prostate cancer has been diagnosed or treated. A shorter doubling time means PSA is increasing more rapidly and is generally associated with a greater risk of cancer progression than […]