AEMCA Practice Exam

Cushing's syndrome is primarily caused by what physiological condition?

1. A tumor on the pituitary gland overproducing ACTH

2. A small growth on the adrenal gland stimulating cortisol overproduction

3. Excessive physical stress on the adrenal glands

4. Genetic predisposition to high cortisol levels

The correct answer is: A tumor on the pituitary gland overproducing ACTH

Cushing's syndrome is primarily caused by an overproduction of cortisol in the body. One of the most common causes of this overproduction is a tumor on the pituitary gland that secretes excessive amounts of adrenocorticotropic hormone (ACTH). ACTH stimulates the adrenal glands to produce cortisol, and when there is a tumor causing this over-secretion, it leads to the hallmark symptoms of Cushing's syndrome, such as weight gain, thinning skin, and high blood pressure. While tumors on the adrenal glands can also directly lead to increased cortisol production, the option relating to the pituitary gland represents the most prevalent cause of Cushing's disease specifically, which is a subset of Cushing's syndrome characterized by a pituitary adenoma. Excessive physical stress or genetic factors may play roles in cortisol regulation but are not direct causes of Cushing's syndrome itself. Understanding the relationship between the pituitary gland, ACTH, and cortisol helps in grasping the pathophysiological mechanisms behind this condition.