Frolic is a playful word with a happy history. It traces back to the Dutch word vroolijk (merry), which in turn evolved from a Middle Dutch combination of vro (happy) and the adjectival suffix -lijc (-ly).
A normal PSA level is considered to be 4.0 ng/mL (nanograms per milliliter of blood). 1  For men in their 50s or younger, a PSA level should be below 2.5 in most cases.  Older men often have slightly higher PSA levels than younger men.
This is because the high PSA levels can stimulate prostate inflammation, dysregulation, prostate enlargement and proliferation of cancerous cells. The following are the percentile ranges of PSA levels: 0 â 2.5 ng per ml = Low. 2.6 â 10 ng per ml = Slightly to moderately elevated.