What Is a PSA Test? Benefits, Harms and How to Decide

The amount of a protein made by prostate cells, in a small blood sample.

The NCI describes PSA as a protein produced by normal and cancerous prostate cells, with levels that tend to rise in cancer but also in other conditions (NCI, PSA Test). A result is given in nanograms per millilitre. There is no single level that separates healthy from not healthy, so doctors look at age, trend and risk.

False alarms, anxiety, biopsies and treatment of cancers that would never have caused harm.

A raised PSA often leads to a biopsy, which carries risks such as bleeding and infection. Treatment such as surgery or radiation can cause erection and bladder problems. Because many prostate cancers grow slowly, some men are treated for disease that would not have harmed them. The NCI covers these trade-offs (NCI, PSA Test).

Men aged 55 to 69 are the group where guidance supports a shared decision, and men at higher risk may start earlier.

Higher risk includes Black men and men with a family history. Men over 70 or with a short life expectancy are usually not advised to be screened. Your doctor can explain how these ideas apply to you. The most important step is to have the conversation before the test, not after.

Tell the doctor about all medicines and supplements, and avoid ejaculation and vigorous cycling for a day or two beforehand if advised.

Say if you take finasteride or dutasteride, as they change the reading. Mention herbal products such as saw palmetto or a blend such as Protoflow. We found no evidence that either changes PSA, but disclosure lets the doctor read your result in full context.

A useful but imperfect test that works best as a shared decision.

Talk to a doctor before you test, and tell them what you take.