There has been a lot of debate about the concept of relative adrenocortical insufficiency (often defined as a reduced response to corticotropin) as a pathophysiological explanation of steroid effects in septic shock. Less is known about the prevalence of absolute adrenocortical insufficiency based on more usual definitions (low baseline and corticotropin stimulated cortisol). A study by Wu and colleagues provides convincing evidence that critically ill patients could evolve from a normal adrenal status towards very low cortisol levels within a few days. Although the exact consequences of these findings deserve more investigation, adrenal testing should not be omitted in patients not improving their hemodynamic status.