What condition results from under-secretion of the adrenal cortex?

The condition that results from under-secretion of the adrenal cortex is Addison's disease. This condition occurs when the adrenal glands do not produce enough of certain hormones, particularly cortisol and aldosterone. Cortisol is crucial for regulating metabolism, immune responses, and stress responses, while aldosterone helps control blood pressure by managing sodium and potassium levels.

In Addison's disease, the lack of these hormones leads to several symptoms, including chronic fatigue, muscle weakness, weight loss, low blood pressure, and darkening of the skin. This typically results from autoimmune destruction of the adrenal glands, although other causes can include infections or adrenal gland tumors.

Other choices represent different conditions unrelated to under-secretion. Cushing's syndrome is associated with excessive cortisol production, pheochromocytoma involves tumors in the adrenal medulla that secrete catecholamines (which can lead to high blood pressure and headaches), and Conn's disease results from excessive production of aldosterone, causing issues with blood pressure and electrolyte balance. Understanding the distinctions between these conditions is essential for effective diagnosis and treatment.