Which of the following symptoms is not associated with secondary adrenal insufficiency?

Hyperpigmentation is primarily associated with primary adrenal insufficiency rather than secondary adrenal insufficiency. In primary adrenal insufficiency, the adrenal glands are damaged and produce insufficient amounts of cortisol and aldosterone, leading to an increase in corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH). This increase in ACTH can stimulate melanocortin receptors, resulting in hyperpigmentation of the skin, particularly in areas exposed to friction or in skin creases.

In contrast, secondary adrenal insufficiency occurs due to a lack of ACTH, often owing to pituitary disorders or suppression from exogenous corticosteroids. Since the stimulation of melanocyte activity by ACTH is reduced in secondary adrenal insufficiency, hyperpigmentation is not a symptom typically observed in these patients.

Symptoms such as weakness, anorexia, and nausea and vomiting are associated with both primary and secondary adrenal insufficiency, as they can result from low cortisol levels affecting metabolism and energy levels.