How is Addison's disease tested on the MCAT?

Question

What is Addison's disease?

How is it tested on the MCAT?

What should I should know about it?

Answer 1

Like Suhas answered, the underlying endocrinology and feedback loops are where you should concentrate. An MCAT passage might ask you about endocrinology, even possibly using something like Addison's as an example, but it won't require you to memorize it specifically.

Answer 2

Addison’s disease occurs when the adrenal glands are either completely or partly damaged and insufficiently produce glucocorticoids and mineralocorticoids. The hallmark symptoms of Addison’s disease are fatigue, dizziness when standing up, and darkening of the skin. 

Now you might be thinking, isn’t this a low-yield concept and a rare disease? How will it be tested on the MCAT? Well, the main way that the exam tests the endocrine system is by assessing your knowledge of negative and positive feedback loops. 

In this case, glucocorticoids and mineralocorticoids will negatively regulate the pathway that stimulates the adrenal glands, specifically ACTH. Therefore, since patients with Addison’s disease don’t produce enough glucocorticoids and mineralocorticoids, this negative feedback loop will be reduced, thus allowing for excess ACTH production. This is why we see elevated ACTH in Addison’s disease patients.