Addison’s disease is a rare condition of the adrenal gland characterized by a gradual, immune-mediated destruction of the adrenal cortex, leading to a deficiency in the adrenal cortex’s hormone production. Enzymes of the steroidogenic pathways in the adrenal cortex are identified as self-antigens, leading to the activation of an autoimmune process that slowly damages all three zones of the adrenal cortex. Antibodies are often directed against the 21-hydroxylase enzyme, which is involved in steroidogenesis. A heightened level of suspicion is essential for diagnosis, as its manifestations frequently overlap with those of many common medical disorders. Addison’s disease can occur in isolation or as part of one of the Autoimmune Polyglandular syndromes; once adrenal insufficiency is confirmed to be of autoimmune origin, the patient should be screened for the associated autoimmune conditions at the time of diagnosis. Management focuses on the optimal replacement of deficient hormones, including glucocorticoids and mineralocorticoids, patient education regarding sick days, and preventing adrenal crises.