Which symptom is commonly associated with Addison's disease?

Hyperpigmentation is a symptom commonly associated with Addison's disease due to the adrenal glands' inability to produce adequate amounts of cortisol and aldosterone. In the absence of these hormones, the body's feedback mechanisms can trigger an increase in adrenocorticotropic hormone (ACTH) production. Elevated levels of ACTH can stimulate melanocytes, the cells in the skin responsible for producing melanin, leading to darkened areas of skin or hyperpigmentation, especially in skin folds, scars, and mucous membranes.

In contrast, weight gain is typically not a feature of Addison's disease; instead, patients often experience weight loss. Excessive sweating and acne are not characteristic symptoms of Addison's disease and could be associated with other hormonal or dermatological conditions instead. Understanding the hormonal imbalances in Addison's disease and their effects on skin pigmentation helps clarify why hyperpigmentation is recognized as a significant symptom of this disorder.