What PSA level suggests prostate cancer?

A prostate-specific antigen (PSA) blood test shouldn’t be used to diagnose prostate cancer on its own, but a raised level may suggest the need for further testing. This is because PSA blood levels can fluctuate due to many reasons, like prostate inflammation, a urinary tract infection, and certain medications. But in general, the likelihood of prostate cancer increases with raised blood PSA levels – around 4.0 ng/mL or above.