I do not recall that my sister was told that she has Addisons Disease - but she has NO Corisol in her system - Cortisol does not even show up in blood or urine tests even though she is taking a very high doses twice a day. Does anyone know what might cause her to not retain it at all?

Is she taking Cortisol (aka Hydrocortisone or Cortef), which would actually show up on the test, or a synthetic like prednisone that would NOT show up, since they are not cortisol.

Both have their advantages, but I prefer the milder Cortef over the more long-acting and stronger prednisone. I can go into reasons why (above and beyond the testing) if you would like.