What causes Cushing's syndrome?

Cushing's syndrome is primarily caused by excessive levels of cortisol in the body. This can result from various factors, including the overproduction of cortisol by the adrenal glands, often due to a tumor in the pituitary gland (known as Cushing's disease), an adrenal tumor, or ectopic production of adrenocorticotropic hormone (ACTH) from tumors located outside the adrenal glands.

Cortisol is a steroid hormone involved in several critical bodily functions, including metabolism regulation, immune response suppression, and stress response. When cortisol levels become excessively elevated, it can lead to a range of symptoms, including weight gain, purple stretch marks, skin changes, high blood pressure, and glucose intolerance, which could lead to diabetes. Thus, recognizing that Cushing's syndrome is fundamentally linked to elevated cortisol levels is essential for understanding its pathophysiology and treatment options.