Which of the following best describes Addison's disease?

Addison's disease, also known as primary adrenal insufficiency, is characterized by the underproduction of adrenal hormones, specifically cortisol and aldosterone. This condition occurs when the adrenal glands do not produce enough of these essential hormones, which play crucial roles in metabolism, immune response, and blood pressure regulation.

In Addison's disease, the lack of cortisol results in symptoms such as fatigue, muscle weakness, and low blood pressure, while decreased aldosterone can lead to issues with sodium and water retention, resulting in dehydration and electrolyte imbalances. This underproduction is typically caused by autoimmune destruction of the adrenal glands or other underlying conditions that impair adrenal function.

The other options refer to conditions that are not associated with Addison's disease. For instance, excess cortisol production is seen in Cushing's syndrome, while increased aldosterone production is related to conditions like hyperaldosteronism. Finally, overactivity of the adrenal medulla is associated with pheochromocytoma, which is a different disorder characterized by excess catecholamine release. Understanding Addison's disease in this context highlights the critical role of adrenal hormones and underscores the importance of hormonal balance in overall health.