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.
PSA levels are measured in nanograms per millilitre of blood (ng/ml). Whether a PSA level is ânormalâ depends on the individual and their age. Cancer Research UK uses the following rough guide: 1  3 ng/ml or lower is considered in the normal range for a man under 60 years old.2  4 ng/ml or lower is normal for a man between 60 to 69 years old. 3  5 ng/ml or lower is normal for a man 70 years old and over.SA levels are measured in nanograms per millilitre of blood (ng/ml). Whether a PSA level is ânormalâ depends on the individual and their age. Cancer Research UK uses the following rough guide: 1  3 ng/ml or lower is considered in the normal range for a man under 60 years old.