The terms 'adrenal asthenia', 'adrenal fatigue' and 'adrenal burnout', sometimes used in lay language, are not a part of the medical or endocrine lexicon. In this opinion piece, we explore the relevance of adrenal asthenia and describe how it can be used in different clinical situations, with varying connotations. Adrenal asthenia may refer to adrenocortical insufficiency, increased parasympathetic or reduced adrenergic tone, or fatigue due to excessive and continuous exposure to stress. It may be mediated by hypoglycaemia or dyselectrolytaemia. The term adrenal asthenia has important clinical and public health advantages.