Prostate-specific antigen (PSA) is a protein produced by the epithelial cells of the prostate gland. Its primary function is to liquefy semen, allowing sperm to move freely. Small amounts of PSA circulate in the bloodstream, and the PSA test measures this concentration in nanograms per milliliter (ng/mL).
The PSA test is a valuable screening tool for prostate health, but it is not a definitive diagnostic test for cancer. Elevated levels can signal conditions such as benign prostatic hyperplasia (BPH), inflammation (prostatitis), or prostate cancer. Preparation for the test aims to avoid temporary, non-medical elevations that could lead to a misleading result and unnecessary follow-up procedures.
Lifestyle Factors to Avoid Before Testing
Sexual activity can cause a temporary spike in PSA levels due to the muscular contractions and pressure involved in ejaculation. These contractions force a higher concentration of the protein from the prostate into the bloodstream, creating an artificially elevated reading. Experts recommend abstaining from all sexual activity, including masturbation, for at least 48 hours before the blood draw to ensure the most accurate result.
Vigorous physical activity, particularly those that place direct pressure on the perineum, can also cause a transient rise in PSA. For instance, cycling or riding a motorcycle can directly stimulate the prostate, leading to a temporary leak of the protein into the blood. Studies have shown that activities like cycling can cause an average increase of nearly 10% in total PSA levels immediately following the activity. To mitigate this mechanical elevation, it is recommended to avoid strenuous exercise, especially cycling, for a minimum of 48 hours before your scheduled test. Light activities such as walking or gentle stretching are considered safe and will not interfere with test accuracy.
Required Waiting Times After Medical Events
Any procedure that physically manipulates the prostate gland causes a significant, temporary elevation in PSA levels, requiring a mandatory waiting period before testing. A Digital Rectal Exam (DRE), where the physician manually checks the prostate, can raise PSA levels; therefore, the blood sample should ideally be drawn before the DRE is performed during the same visit. If a DRE is performed first, waiting at least 3 days to a week is suggested before proceeding with the blood test.
Procedures that cause more trauma necessitate a much longer delay to allow inflammation to fully resolve. A transurethral resection of the prostate (TURP) or a prostate biopsy, which involves collecting tissue samples, significantly elevates PSA. Following a prostate biopsy, a waiting period of at least six weeks is necessary to ensure the PSA has returned to its baseline level.
Infections or inflammation of the urinary tract or prostate, such as prostatitis or a urinary tract infection (UTI), are also common causes of high PSA readings. Testing must be postponed until the infection is completely cleared and all associated inflammation has subsided. This typically requires a delay of four to six weeks after the infection has been successfully treated. Scheduling the test during an active infection would produce a falsely high result, potentially triggering unnecessary follow-up procedures.
Short-Term Dietary Considerations
Immediate dietary changes can play a minor role in ensuring the most accurate reading by minimizing prostate irritation just before the test. Staying well-hydrated is helpful, as dehydration can sometimes complicate blood draws. Limiting consumption of alcohol and high-caffeine beverages in the 24 hours prior to the test is often recommended. These substances can act as mild bladder and urinary tract irritants, potentially causing minor, transient inflammation. Avoiding overly spicy foods in the day or two before the test is also a cautious measure, as they have been linked to inducing inflammation in some men.
It is important to inform your healthcare provider about all medications and supplements you are currently taking. Certain drugs, such as 5-alpha reductase inhibitors used for BPH, can artificially lower PSA levels and must be accounted for when interpreting results. Never stop taking a prescribed medication without explicit direction from your physician, who can adjust the interpretation of your test score.
Interpreting Results and Next Steps
Even after following all pre-test instructions, an elevated PSA level may still be identified, which does not automatically mean a diagnosis of prostate cancer. Many non-cancerous conditions, including an age-related increase in prostate size (BPH), can cause the PSA concentration to rise. The PSA score is simply one piece of information that must be considered alongside your age, overall health, and the results of any physical examination.
If an initial result is high, the most common next step is to repeat the test after a waiting period of approximately four to six weeks. This retest confirms whether the elevation is persistent or was merely a temporary fluctuation. If the score remains elevated, the physician will then look at the rate of change over time, known as PSA velocity, and may recommend further diagnostic steps.
It is necessary to discuss your results with a qualified physician, such as a urologist or primary care provider. They are trained to interpret the score in its full clinical context and determine the most appropriate course of action. This may involve additional blood tests, imaging like an MRI, or a prostate biopsy to definitively determine the cause of the persistent elevation.