hi there, this is something i've mentioned before but i'm just putting it up on its own, mostly for newbies who might not have had as much experience with tests and so forth. i figured it out since my dx; i apologize if i'm stating the obvious to some! so here goes:
if you ever get your blood tested for anything and the result comes back as "normal", that is normal as in statistics normal, bell curve and all that.
so, if you end up with a result that is close to one end or other of the normal range, it has a very different meaning to a result that is in the centre of the normal range.
what i have not yet been able to determine is whether the peak of the bell is meant to be dead centre of the normal range, or not. i'm also not convinced that the peak of the bell represents "optimal" values.
as posted elsewhere, the uric acid example:
at my lab, normal range for UA is 150-350. my level is 194. so i'm normal. sounds good right? but in fact 194 is the exact average for ms patients. at a guess, most people actually have levels around 250. and, based on the average level in healthy controls, 290 is "optimal".