A "high" PSA is relative to the patient's age and race...younger people have a lower threshold for elevation in PSA. There are specific guidelines established.
The Standard of Care for "elevated PSA" would be a Prostate Bx, which if negative would reset the PSA threshold...therefore a 50 year old man with a PSA of 3.4 and a negative bx, the following year, if he has a PSA of 3.6 the number is high, but the "PSA Velocity" is not, and there would be less cause for concern.