Glucocorticoid treatments inhibit adrenal axis at the hypothalamo-pituitary level. This inhibition decreases ACTH plasma levels, leading to unpredictable secondary adrenal insufficiency after glucocorticoids withdrawal. Almost half of the patients will present with corticotrop axis suppression after long term glucocorticoid treatment. Glucocorticoid dose and duration of treatment might be linked to hypothalamic-pituitary-adrenal suppression; but some not yet clearly identified individual parameters are also important. After long-term glucocorticoid treatment, in order to reduce the risk of clinical sign of adrenal deficiency, the glucocorticoid dose is progressively decreased. When the daily glucocorticoid dose is tapered below 5 mg/day of equivalent prednisone, a hydrocortisone substitutive treatment can be started. Before discontinuation of the treatment the full recovery of the corticotrop axis could be assayed by corticotropin stimulation test.