A 32-year-old male presents with hypotension and skin hyperpigmentation. What is the most likely diagnosis?

The presentation of hypotension and skin hyperpigmentation is most consistent with Addison disease, which is a form of primary adrenal insufficiency. Addison disease is characterized by a deficiency of glucocorticoids, mineralocorticoids, or both due to damage to the adrenal glands. The lack of cortisol leads to increased production of adrenocorticotropic hormone (ACTH) from the pituitary gland, which can stimulate melanocyte activity, resulting in hyperpigmentation of the skin, particularly in sun-exposed areas, scars, and skin creases.

The hypotension observed in Addison disease is primarily due to the deficiency of aldosterone, which normally helps maintain sodium and water balance, thus contributing to blood pressure regulation. In patients with Addison disease, the inability to retain sodium and consequently water leads to volume depletion, manifesting as hypotension.

In contrast, while pituitary insufficiency could also lead to hypotension due to decreased levels of ACTH and subsequently low cortisol production, it does not typically present with hyperpigmentation. Cushing syndrome usually involves hypercortisolism, which often causes hypertension rather than hypotension, along with other symptoms such as obesity and skin changes, but hyperpigmentation is less common. Primary aldosteron