The Prostate-Specific Antigen (PSA) test is a common blood test used primarily to screen for prostate issues, most notably prostate cancer. This test measures the concentration of PSA, a protein naturally produced by the prostate gland, in the bloodstream. Since an elevated PSA level can lead to further medical procedures, understanding how common behaviors like ejaculation affect the results is important for obtaining a reliable reading. The PSA level can be temporarily influenced by various daily activities.
Understanding the PSA Test
The PSA test measures the amount of prostate-specific antigen circulating in the blood, typically reported in nanograms per milliliter (ng/mL). PSA is a protein produced by cells within the prostate, a small gland situated beneath the bladder. Its function is largely to help keep semen in a liquid form so that sperm can move freely.
The test is used to screen men for potential prostate cancer and to monitor those already diagnosed or treated for the disease. While higher PSA numbers are associated with a higher risk of cancer, the test is not diagnostic on its own. Non-cancerous conditions, such as inflammation or an enlarged prostate, can also cause the PSA level to rise. Interpretation must consider the patient’s age, overall health, and other contributing factors.
The Impact of Ejaculation on PSA Levels
Ejaculation temporarily increases the concentration of PSA in the bloodstream, potentially leading to a falsely elevated test result. This temporary rise involves the contraction of the prostate gland during ejaculation. This muscular action forces a small surge of the PSA protein out of the prostate tissue and into the surrounding blood vessels.
Studies show this increase can be statistically significant, though the effect is usually minimal for most men. A slight elevation in a patient with a borderline-high reading could push the result into a concerning range. The PSA level usually returns to the true baseline within 24 to 48 hours following the activity.
Pre-Test Preparation Guidelines
To ensure the PSA test provides the most accurate reflection of prostate health, healthcare providers recommend specific actions before the blood draw. The most important instruction is to abstain from all sexual activity that involves ejaculation for a set period. The standard recommendation is to avoid intercourse, masturbation, and nocturnal emissions for at least 48 hours before the test.
Physical Activity and Exams
Certain physical activities should also be avoided in the 48 hours leading up to the test. Vigorous exercise, such as intense running, heavy weightlifting, or cycling, can cause a temporary rise in PSA levels. Cycling is particularly noted because the sustained pressure of the bicycle seat directly on the prostate can cause mechanical irritation.
Another element to consider is the timing of a Digital Rectal Exam (DRE). The physical manipulation of the prostate during this exam can likewise cause a temporary PSA increase. If a DRE is necessary, it is often performed after the blood sample has been taken.
Other Factors Influencing PSA Results
Beyond immediate physical activity, several other medical factors can influence PSA levels. Benign Prostatic Hyperplasia (BPH), the non-cancerous enlargement of the prostate, commonly causes a gradual rise in PSA over time. Prostatitis, an inflammation or infection of the prostate, also leads to elevated PSA levels due to the body’s inflammatory response.
A recent procedure, such as a prostate biopsy, causes a significant and prolonged spike in PSA that can last for several weeks. For this reason, it is recommended to wait at least six weeks after a biopsy or a urinary tract infection (UTI) before undergoing a PSA test.
Medications
Certain medications also affect PSA concentration, most notably 5-alpha reductase inhibitors like finasteride and dutasteride. These drugs are prescribed for BPH and can lower the PSA level. Patients taking these drugs should inform their doctor, as the result may need to be adjusted for accurate interpretation.