An Addison disease revealed with a serious hyponatremia.

We present the case of an Addison's disease revealed by a serious hyponatremia. The serum concentration of ACTH and 21-hydroxylase antibodies were increased and lead to the diagnosis. The cortisol blood level was lowered but required to take into account the stress induced by the hospitalisation of the patient. Addison's disease is characterized by the destruction of the adrenal cortex. Autoimmune adrenalitis is the main cause of adrenal insufficiency. Treatment involves normalisation of sodium concentration and corticosteroids replacement. With a good patient compliance, the survival rate of Addisonian patient is similar to that of the normal population. Management of patient requires vigilance because of the occurrence of others autoimmunes diseases during patient life.