What causes Cushing's Disease?

Cushing's Disease is primarily caused by an excess production of cortisol, a steroid hormone produced by the adrenal glands. This condition often arises from a tumor on the pituitary gland that secretes high levels of adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal glands to produce too much cortisol. The elevated cortisol levels can lead to various symptoms, such as weight gain, a rounded face, and high blood pressure, among others. Understanding this mechanism is crucial for recognizing the impact of cortisol on the body and the specific nature of Cushing's Disease.

The other options relate to different hormonal imbalances or deficiencies unrelated to Cushing's Disease, such as insulin deficiency (relevant to diabetes), insufficient thyroid hormone (which leads to thyroid disorders), and high adrenaline levels (which can cause stress-related symptoms). Thus, the understanding of excess cortisol production as the correct cause of Cushing's Disease highlights the specific dysfunction of hormone regulation associated with this condition.