What defines a PSA?

What Is a PSA and Why Does It Matter?

Prostate-specific antigen, commonly known as PSA, is a protein made by cells in the prostate gland—both healthy ones and, potentially, cancerous ones. All men have some level of PSA in their bloodstream, and that’s completely normal. But when doctors talk about PSA levels, they’re usually looking for changes that might signal a problem.

A high PSA reading can raise a red flag for prostate cancer, which is why it’s often used in screenings. But here’s the thing: elevated PSA doesn’t automatically mean cancer. Plenty of non-cancerous conditions can boost PSA levels, including an enlarged prostate (a common issue as men age) or even recent sexual activity.

For example, ejaculating within the past 48 hours can temporarily increase PSA, which is why some doctors recommend abstaining before a PSA test. Inflammation or infection in the prostate, known as prostatitis, can also cause levels to spike. Even a vigorous bike ride—or a recent medical exam involving the prostate—might affect the results.

That’s why interpreting PSA isn’t black and white. Doctors don’t make decisions based on one number alone. Instead, they look at trends over time, your age, family history, and other factors. A slightly elevated PSA might lead to repeat testing, not immediate treatment.

Ultimately, the PSA test is just one tool in a broader conversation about men’s health. While it plays a key role in early detection, it’s not a definitive diagnosis. The real value comes from understanding the full picture—and having a doctor who helps you navigate it without jumping to conclusions.