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.
What does PSA mean â Prostate Specific Antigen What is PSA? Prostate Specific Antigen PSA, is an enzyme found in the blood produced exclusively by prostate cells. Normal levels of PSA in the blood are small amounts between 0-2.5 ng/ml. Higher than normal levels, greater than 2.5 ng/ml, can be caused by cancer or benign, non-cancerous conditions such as enlarged prostate, prostate inflammation, infection, or trauma. All elevated readings of PSA should be checked.