As glucose levels vary so much (like 150 after a meal to 90 or so area when hungry); to test glucose levels at a well-baby doctor visit wouldn't really indicate much (they vary too much according to when last ate and what was eaten).  For other med conditions like diabetes, thyroid, and for pregnant women (gestational diabetes) - there is the glucose fasting test (don't eat, then drink that orange liquid, then test glucose).  It wouldn't surprise me if glucose levels were checked automatically by endos (at lab work times) - but these really wouldn't mean much unless the fasting-type test was done, so one would know exactly why glucose levels were too high or too low after xx hours of not eating (as in an insulin problem).  If you've ever been given an IV when in pregnancy labor, it was to get glucose & sodium into you at a time they don't want you to be eating anything.  If you look at an IV bag, you'll see the % sodium and/or % glucose solution (usually 5-10% glucose).  The blood glucose test just takes seconds and anyone can do it (take a finger prick of blood, a few seconds later you know the glucose level - the nurse will do it & has the test kit right there with her, she'll know the level instantly).  The sodium/potassium, etc. panel needs a vial of blood drawn from the person, then to the lab for testing (they may also restest glucose level in the lab vs. the quick test above).  So if you take your ill child to the ER, they'll draw the blood for electrolyte panel, but you may also see the nurse or lab technician prick the finger for a quick glucose test (to give them an immediate indication of things vs. waiting for the lab work).  So while they are awaiting labwork for the electrolyte results, they were immediately able to get the glucose results (an immediate IV if glucose was low).  Like Shaun was told, and that is something I'd never heard of but makes complete sense, to give 1/2 - 1 glucose tablet for high activity level things.   That's an excellent idea and I'm going to remember that and do it because of reading how "wiped out" many CAH people are after some sports time.  If you look at adrenal crisis symptoms, you'll see 'low blood glucose' on that list.  I've asked several endos about if they thought keeping glucose tablets on hand was a good idea; all but one told me "yes"; and I can't comment here which endo told us "no" (but here I'll ad that I had a CAH child die ... hint, hint).  You figure in the morning after a night's sleep, your child hasn't eaten for 8 or more hours, so blood glucose is probably low (but would be ok after eating breakfast).  If, your child wakes up sick or just not feeling too great in the morning, and doesn't eat well, then their blood glucose level isn't going to get back to a good range.  You could have that child drink orange juice, fruit juice, or other sugary drink, but the child may not readily drink that 8 oz or so too well.   A glucose tablet is just like a piece of candy, even when ill, Amanda will always take that tablet (it's like candy).   I just use them as a "precaution" and to fuel-up Amanda's body when she is ill (or on the rare occasions she doesn't seem to be eating too greatly in a day).