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.
1 Men in the range of 60 to 69 years have normal PSA levels that are less than 4.5 ng/mL. 2  Men over the age of 70 years have normal PSA levels that are less than 6.5 ng/mL.3  It is also important to note that the normal ranges of PSA results may vary from one laboratory to another. Men over the age of 70 years have normal PSA levels that are less than 6.5 ng/mL. 2  It is also important to note that the normal ranges of PSA results may vary from one laboratory to another. 3  The abbreviation ng/mL stands for nanograms per milliliter.