Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which of the following is not a feature of secondary adrenal insufficiency?

1. Hyperkalemia

2. Low corticosteroid production

3. Low ACTH levels

4. Nausea

The correct answer is: Hyperkalemia

In the context of secondary adrenal insufficiency, hyperkalemia is not typically associated with this condition. Secondary adrenal insufficiency occurs when there is inadequate stimulation of the adrenal glands due to insufficient adrenocorticotropic hormone (ACTH) production from the pituitary gland. In this scenario, there is often low corticosteroid production; however, the adrenal glands themselves are generally intact and can produce some hormones if adequately stimulated. Low ACTH levels are characteristic of secondary adrenal insufficiency since it originates from a defect in the pituitary gland rather than the adrenal glands themselves. Symptoms such as nausea can occur due to the lack of corticosteroids that are necessary for various physiological functions, including regulating metabolism and mitigating stress responses. Hyperkalemia, on the other hand, is more commonly seen in primary adrenal insufficiency (Addison's disease), where there is a deficiency of aldosterone, leading to difficulties in potassium excretion and subsequently an accumulation of potassium in the blood. Thus, in secondary adrenal insufficiency, a person typically does not present with hyperkalemia, making it the correct choice for this question.