I guess I'm a bit confussed with regards to the renin levels. My son has always been very well controlled so I'm not familiar with the over/under suppression. We've only ever had two minor adjustments with his cortef; at about 2yrs and just recently 5.4yrs. As I have understood the changes it has just been due to growth. The only other change was as an infant and it was with the florinef. What confusses me about the renin is this. The first change made to my son was the florinef because his renin levels were, if I remember correctly, 30. I thought I had been told that the higher the renin level the worse it was. Apparently for my son 30 had been high although within the acceptable range. It was explained to me that if your salt is high then your potassium is low and visversa. Because our children don't produce Aldosterone, which causes the kidneys to retain sodium (not to dehydrate) and excrete potassium (not to have cardiac arrest) they needed to be given the florinef. Apparently the lack of Aldosterone causes the kidneys to work backwards. Giving the florinef forces normal function. So... what I guess I'm saying is if your son's renin levels are already low then I would think that is good and he is retaining his salt and excreeting the potassium. So... why the increase in the florinef?