psa

PSA is an acronym that can refer to several different terms. Two of the most common are prostate-specific antigen, a protein produced by the prostate, and public service announcement, a message issued to the public for information or safety.

Prostate-specific antigen (PSA) is a glycoprotein enzyme produced by the prostate. A PSA test measures its concentration in the blood and is used in screening for prostate cancer, as well as to monitor treatment and detect recurrence. PSA is reported in nanograms per milliliter (ng/mL); higher values may indicate cancer but can also result from benign conditions such as prostatitis or benign prostatic hyperplasia. Factors such as age, recent ejaculation, prostatitis, instrumentation, and vigorous exercise can affect PSA levels. To improve specificity, clinicians may use strategies such as PSA velocity (the rate of change over time) or the ratio of free to total PSA. Screening recommendations vary by country and organization and generally emphasize informed, shared decision-making.

Public service announcements are messages intended to inform or warn the public about issues affecting health, safety, or civic life. They are typically distributed by government agencies, non-profit organizations, or media outlets and may appear on radio, television, print, or online platforms. PSAs are usually non-commercial and time-limited, often addressing topics such as disease prevention, natural hazards, or safety campaigns. Examples include anti-smoking campaigns, seatbelt reminders, and safe driving messages.

The acronym PSA may have additional meanings in different sectors, but the two above are among the most widely encountered in everyday usage.