The Prostate-Specific Antigen (PSA) test is a common blood test used to assess prostate health. Understanding the necessary preparations for this test is important for accurate results.
The Fasting Question
Fasting is generally not required before a PSA blood test. The levels of prostate-specific antigen in the blood are not significantly affected by food or drink consumption. This distinguishes the PSA test from other common blood tests, such as those for cholesterol or blood glucose, where fasting is often a strict requirement. You can typically eat and drink normally before your appointment. Scientific evidence does not link the consumption of specific foods or beverages to elevated PSA levels.
Essential Preparations Beyond Fasting
While fasting is not a concern, several other factors can influence PSA test results and require specific preparation. Being mindful of these can help ensure the accuracy of your test.
Ejaculation can temporarily elevate PSA levels, potentially leading to misleading results. It is recommended to abstain from sexual activity, including masturbation, for at least 48 hours before your PSA test.
Vigorous physical activity can also transiently increase PSA levels. Activities like cycling, running, or strenuous exercise should be avoided for at least 48 hours before the blood test. Light exercise, such as walking or stretching, is generally considered acceptable.
It is important to inform your doctor about all medications, supplements, and herbal remedies you are taking. Certain medications, like 5-alpha reductase inhibitors (e.g., finasteride or dutasteride) used for benign prostatic hyperplasia (BPH) or hair loss, can lower PSA levels, potentially masking prostate issues. Conversely, some drugs, including certain nonsteroidal anti-inflammatory drugs (NSAIDs), statins, and testosterone replacement therapy, might influence PSA levels.
Recent medical procedures involving the prostate can also affect PSA levels. A prostate biopsy, for example, can significantly raise PSA for several weeks, and it is generally advised to wait at least six weeks after such a procedure before a PSA test. A digital rectal exam (DRE), which involves physically examining the prostate, can also temporarily increase PSA levels; therefore, the PSA blood draw is often performed before a DRE. If you have had a recent urinary tract infection, your doctor may recommend waiting until the infection has cleared before proceeding with the test.
What is a PSA Test?
The Prostate-Specific Antigen (PSA) test is a blood test that measures the amount of PSA in your blood. PSA is a protein produced by both normal and cancerous cells in the prostate gland, a small gland in males located below the bladder. The prostate’s main function is to produce seminal fluid, and PSA helps to liquefy semen, allowing sperm to move freely.
Small amounts of PSA are normally found in the bloodstream. However, elevated levels can indicate various prostate conditions, including benign prostatic hyperplasia (an enlarged prostate), prostatitis (inflammation or infection of the prostate), or prostate cancer. A high PSA level does not automatically mean cancer is present. The test serves as a screening tool to help identify individuals who may need further evaluation, rather than a definitive diagnostic test for cancer itself.