Which age group does acromegaly most commonly affect?

Correct Answer: A

Rationale: Acromegaly most commonly affects individuals in the age group of 30-50 years. This condition is typically diagnosed in adults between these ages. Acromegaly is often caused by the overproduction of growth hormone in adults, which leads to excessive bone growth and tissue expansion. While acromegaly can develop at any age, it is more commonly seen in adults within the 30-50 age range.

Correct Answer: D

Rationale: The most common cause of Cushing's syndrome is a pituitary adenoma, specifically a corticotroph adenoma. This adenoma leads to excessive secretion of adrenocorticotropic hormone (ACTH) by the pituitary gland, which in turn stimulates the adrenal glands to produce high levels of cortisol. This results in the symptoms and signs characteristic of Cushing's syndrome. Pituitary adenomas are responsible for around 70-80% of cases of Cushing's syndrome, making it the most common cause.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Nephrogenic diabetes insipidus (NDI) is a condition where the kidneys are unable to respond to antidiuretic hormone (ADH) as they should, leading to excessive urination and extreme thirst. One of the main causes of nephrogenic diabetes insipidus is the use of certain medications, with lithium being the most common culprit. Lithium can interfere with the kidney's response to ADH, resulting in decreased water reabsorption and the characteristic symptoms of diabetes insipidus. Other causes of NDI can include genetic mutations affecting the vasopressin receptor gene or other underlying conditions such as hypercalcemia, hypokalemia, or obstructive uropathy.

Correct Answer: A

Rationale: Addison's disease, also known as primary adrenal insufficiency, is a condition where the adrenal glands do not produce enough steroid hormones, mainly cortisol and sometimes aldosterone. This deficiency in steroid hormone production is typically caused by autoimmune destruction of the adrenal cortex. Without enough cortisol and aldosterone, various symptoms may arise, such as fatigue, weight loss, low blood pressure, and skin discoloration. Therefore, option A accurately describes the nature of Addison's disease.