Which finding is most commonly associated with Addison's disease?

In Addison's disease, the adrenal glands do not produce enough hormones, particularly cortisol and aldosterone. One of the hallmark findings associated with this condition is increased pigmentation of the skin and mucous membranes, often termed hyperpigmentation. This occurs due to elevated levels of adrenocorticotropic hormone (ACTH), which can stimulate melanocytes, leading to darker skin.

Patients with Addison's disease might also exhibit other symptoms due to the lack of cortisol, such as fatigue, weight loss, and hypotension, but increased pigmentation is a distinctive and striking feature that can often serve as a clue in diagnosis. It is most prominently seen in areas exposed to sunlight, as well as in skin folds and scars, providing an important clinical marker for healthcare providers when assessing patients who may have adrenal insufficiency.