My acetaminophen levels were <2 ug/ml. my results were flagged as low. normal range is 10-30 ug/ml. what does this indicate? should i be concerned?

Normal, if not on it: Whether one should worry or not depends on why the test was ordered. Everyone has the lowest value for his or her blood acetaminophen level, until a medication containing acetaminophen is taken. The normal level for a person not on Tylenol (nor taking another acetaminophen drug) would be zero, close to zero, or whatever the lowest possible lab result is.