Acid-base homeostasis is fundamental for the maintenance of life. Subclinical hypercortisolism (HS) is an entity that is difficult to diagnose as it does not present a noticeable symptomatological picture without advanced resources for clinical practice. The objective of this chapter is to discuss the importance of recognizing this entity and establishing differential diagnosis. Characterization of those elements is the way for provide a good clinical practice and avoid mistakes. The cortisol and other glucocorticoids which have the ability to stimulate gluconeogenesis are the target of his study. An up-to-date approach is proposed. This is a narrative review carried out between 1993 and 2024. The following databases were used: DOAJ Directory of Open Access Journals; PubMed, PubMed(Medline).