Hi Chris, Thank you for your kind words. Yes, this CAH is maddeningly complex. Just when I think I understand one aspect of it pretty well, I think of a zillion things I don't understand, at all. I started writing down a list of questions for our endo earlier today, based on one teeny test result, and before I knew it, my list of questions was three pages long. He is usually very quick to respond to my email messages, but I haven't heard from him yet. No wonder---he must be trying to avoid me (ha, ha). To answer your questions: 1. The LHRH test is a test for pubertal activity. My son had it done because he had a bone age of around 13, when he was diagnosed, the age around which puberty would normally start for a boy. You would not need to worry about it at this point for Jack, and in fact, may never need to worry about it. Since Jack was diagnosed at birth and has been treated since then, if he is well controlled throughout his childhood and is able to reach puberty at the right chronological age and bone age, it may never be an issue for you. We need to worry about it with my son because he is at the brink of puberty, even though he is only 7. If he were allowed to go into puberty, his testicles would start producing testosterone in large quantity. A small amount of testosterone is also produced in the adrenal glands. The conversion of testosterone into estrogen, I believe, is what causes premature skeletal maturation and advanced bone age. Once the testicles go into action, you are dealing with a whole lot more testosterone, so that process gets speeded up , along with all the other changes that happen with sexual maturation. Basically, the LHRH test is a challenge test, similar in concept to the ACTH stim. test. A needle is inserted in the arm and blood levels of LH and FSH are read every 15 minutes, for one hour. When central puberty happens in a child, the hypothalmus releases a hormone called GnRH (Gonadatropin Releasing Hormone), which in turn, stimulates the pituitary to produce LH (luteinizing hormone) and FSH (follicle stimulating hormone). Measurement of LH and FSH levels at these 15 minute intervals determine whether or not a child has chemically begun puberty. (I still haven't figured out why they call this an LHRH test, rather than an LHFSH test.) Because Nick was shown to have some pubertal activity as a result of his LHRH stim. test, we do need to control testosterone production from both places. The steroids that he takes---in his case dex, instead of cortef--- controls the adrenal glands. To control the production of LH and FSH, he takes a Lupron shot monthly, which quiets down the activity in the hypothalmus and the pituitary glands. Actually, Lupron works by stimulating the hypothalmus to produce MORE GnRH, rather than less. Apparently, LH and FSH are only produced if GnRH is released in short spurts, or pulses. When there is a steady stream of GnRH, the system actually becomes "desensitized" and stops producing LH and FSH. Lupron, therefore, works by causing this desensitization process. Interesting, huh? It's complex, because when we get a high testosterone reading, we have to determine whether or not it's coming from the adrenals or the testicles, so we can determine which med. to adjust---it's a constant balancing act. When one is controlled, the other one seems to get out of whack, and vice versa. 2. As far as the values for the 24 hr. urine test: They are totally different from 17 OHP numbers. Basically, the urine measures something called 17-ketosteroids. What they are are essentially the metabolized form of the adrenal hormones---kinda a mishmash of progesterone, 17 OHP, androstenedione, and testosterone, rolled into one. This used to be the standard test for measuring hormonal control, but as you mentioned, is difficult to get in very young children. My endo likes this test, in addition to the blood work, because he feels it gives a good indication of what happens with hormone levels across 24 hrs., unlike blood, which reflects only the value at the exact time that it's drawn. Measurement of 17 KS is on a whole different scale. For a child of Nick's age, a value of around 2.0 mg/24 hrs. is considered normal. That's why when Nick's urine was recently 2.7 (close to normal), though his morning 17 OHP was above 2000, his endo felt it meant only that his dose was wearing off by morning, and needed to be adjusted slightly upward, not that he was out of control for the greater part of the day. In a way, information received from a 24 hr. urine collection is similar to getting finger sticks at different times of the day---it has the advantage of telling the story of what happens over the course of an entire day. At the same time, it has the disadvantage of not distinguishing the particular hormone(s) that is elevated. That is why sometimes, a combination of the two seems to tell a more complete story. 3. As far as ACTH numbers and how they reflect level of control: I would assume that good adrenal control would equal low ACTH, but don't quote me on that. I'm not sure what happens with ACTH if, in our case, the adrenals are well controlled, but there is pituitary activity. I know our endo measured ACTH the last two tests, but I was so focussed on testosterone and 17 OHP values, that I forgot to ask him what they were. Thanks for reminding me to ask him. That was one of the questions on my list. Sorry again for the long post---and you thought YOU were long winded. It's true, once I get started thinking about this CAH thing, it's hard to stop. Hope this helped to answer your questions! Carol