The Real Difference Between Addison's & Cushing's with Memory Tricks

Addison’s disease vs Cushing syndrome can feel like a maze of arrows, hormones, and “wait, which one is high?” moments. We cut through the noise by building the whole story from the ground up: what the adrenal glands do, which adrenal cortex hormones actually matter for exams and clinical reasoning, and how one simple feedback loop explains most of the lab patterns you’ll see.

We walk through aldosterone (the salt hormone) and cortisol (the stress hormone) in plain language, then map the HPA axis step by step: stress triggers CRH, CRH triggers ACTH, and ACTH triggers cortisol. From there, everything becomes a logic problem. If cortisol is high, what should ACTH do? If cortisol is low, what does the pituitary try next? We also clarify the key difference between Cushing disease (pituitary-driven, ACTH high with cortisol high) and Cushing syndrome (adrenal or exogenous steroid source, ACTH low with cortisol high), and we contrast that with primary vs secondary Addison’s patterns.

You’ll leave with practical memory tricks, a clearer way to think about endocrine disorders, and a framework you can reuse for questions on cortisol, ACTH, and adrenal gland physiology. Check the links for free Addison’s and Cushing’s practice questions, then subscribe, share the episode with a classmate, and leave a review so more nursing students can find it.

To submit your stories & comments, visit: https://simplenursing.com/podcast/

Transcript

Addison’s Vs Cushing’s Overview

Adrenal Glands And Key Hormones

HPA Axis And Negative Feedback

Cushing Disease Vs Cushing Syndrome

Addison’s Primary Vs Secondary

Memory Tricks Plus What’s Next

Free Questions And Subscribe

SPEAKER_00 0:02

Woo! We got a code brown. Welcome to Bedpan Banter. With me, Nurse Mike, the death of nursing. Can I get a Bedpan over here? Welcome to Bedpan Banter, the official podcast of Simple Nursing, where we chat all about the human side of healthcare. I'm your host, Nurse Mike, and today we're breaking down one of the most complex topics, Addison's disease versus Cushing syndrome. And by the end of this episode, you will completely understand the difference. In this episode, you'll get a solid overview of how the adrenal glands work, the difference between Addison's and Cushing, and how to start thinking about what's happening in the body. We'll cover the basics first, and then in part two, we're gonna dig a little bit deeper into labs, signs and symptoms, and the nurse's role in both conditions. So buckle up, here we go. So first of all, what the heck are the adrenals? Well, the adrenal glands sit on top of the kidneys and they make hormones that control blood pressure, blood sugar, stress response, fluid balance, and metabolism. The outer part of the adrenal gland is called the adrenal cortex, and it makes steroid hormones, which helps the body to respond to stress. So these are the ones we talk about with Addison's and Cushings. Now let's go over what these hormones are. The main hormones to know is aldosterone, cortisol, and antigens. So first off, eldosterone. Think the salt hormone. It helps to keep sodium and potassium balanced and controls blood pressure and fluid volume. Next is cortisol. For this hormone, think sugar. Cortisol is known as the stress hormone. It helps the body to use glucose for energy, and overall, it helps the body to respond to stress. Now, lastly, we have androgens. For this one, think sex hormones. They can be affected in addictions and cushions, but they're not the main focus here. So here's the key takeaway Addisons and Cushings are mainly about cortisol and aldosterone. But the main thing you should hone in on are those two steroids, cortisol and aldosterone. Now that we know the hormones, we need to understand the HPA access because this is what explains the following why ACTH and cortisol labs look different depending on the cause, and why cushion disease and cushing syndrome are not the same thing. So here's the pathway for the HPA access. It's super simple. So think number one, stress happens. Number two, the hypothalamus releases CRH. And CRH is that corticotropin releasing hormone. Now CRH is what tells the pituitary to release ACTH, and ACTH is that adrenocorticotropic hormone. Now ACTH tells the adrenal cortex to release cortisol, our stress hormone. So one more time to review the HPA access order. Stress induces the hypothalamus, which releases CRH, then the pituitary releases ACTH, which signals the adrenal cortex to finally release cortisol. Now, once cortisol is high, the body should shut down CRH and ACTH release. This is called a negative feedback or a negative feedback loop. So the HPA access is supposed to be that negative feedback loop. Now, if the feedback loop breaks, that's when we develop addisons or cushions. So remember this: write this down. Cortisol stays high with cushions, the double C's there. And also be sure to write down cortisol stays low in Addison's. That's why we have to say add some cortisol with addisons. And this is why the source of the problem matters, because it changes ACTH levels differently. Think of ACTH like the boss telling the adrenal cortex how much cortisol to make. Now, here's the key part. If the problem starts in the pituitary, well then ACTH stays high because the boss keeps ordering the adrenal gland to make cortisol. The situation is called cushing disease. Basically, a big, huge cushion of cortisol. But if the problem starts in the adrenal gland itself, the key term there is the adrenal gland, or if cortisol is coming from outside steroid use, well, then the brain senses high cortisol and shuts off ACTH. In that situation, it's called Cushing syndrome. So cushing disease, simply think, pituitary problem, and ACTH is high, so cortisol is high. And Cushing syndrome, adrenal or outside source, ACTH is low and cortisol is high. And that's why the source of the problem is so important. Now here's a memory trick for Cushing syndrome versus Cushing disease. For Cushing disease, think of the D for disease and P for pituitary, D and P. So dumb pituitary. It's not doing its job. It's a pituitary problem. Now for Cushing syndrome, think of the S here, for it's something else, because something else is affecting steroid levels, aka the adrenals, or outside steroid use. So now that we've gone over some cushing issues, you're probably confused and are thinking, well, what's happening with Addison's disease then? I know it's a lot of information to absorb, so let's take it slow. But always remember, Addison's is the opposite of cushions. So again, with Addisons, we need to add some steroids, like cortisol. And cushions, we have a lot of cushion of cortisol. So instead of cortisol being too high, cortisol is now too low with Addiscons, because again, we have to add some cortisol. This is because the adrenal glands aren't making enough steroid hormones. So what happens to ACTH? Well, again, it depends on where the problem starts. So the problem here is the adrenal gland itself. Adrenal cortex can't make cortisol, and often aldosterone too. So in result, cortisol stays low. The brain senses the low cortisol, and that's when the pituitary increases ACTH to try to stimulate the adrenal glands. So here's the result. ACTH is high, which would normally make cortisol high, but our adrenal glands are broken. So cortisol is low. This is the classic Addison's disease scenario. Now, Addison's can be an adrenal problem, but it can also be a pituitary problem. So for secondary Addison's disease, the problem is in the pituitary and not the adrenal. So this is what happens when the pituitary doesn't release enough ACTH. In this case, the adrenals aren't being told to make cortisol. And so in a result, cortisol stays low. Now this is less common, but it's still important. I know this is a lot, so listen to the section again. And what might help you is to draw the HPA access out on paper. First the normal function, then cushing syndrome versus cushion disease. And finally, for Addison's syndrome versus Addison's disease. And in this way you can clearly identify which hormone levels go up or down in each one. And you can identify where the problem starts. Now let's review some memory tricks to help this stick. Think cushions as cortisol is too high, too much cushion of cortisol. And on the opposite side, Addison's cortisol is too low. So we have to add some cortisol with Addison's. And remember, the ACTH changes based on where the problem starts. So if the adrenal glands are broken, well then ACTH is high. And if the pituitary glands are broken, well, ACTH is low. So now we're going to dive deeper into Addison's and Cushings. So be on the lookout for part two, where we'll break down more memory tricks for lab values and signs and symptoms and a whole lot more. Now before I go, I do have some good news for you. We have some free practice questions that you can check out specifically on this topic Addisons and Cushings. And so we're going to link those in the description for you to test your knowledge. Or if you want to change things up, you can simply head to SimpleNursing.com to sign up for a free trial and access lots of additional topics. And as always, thank you so much for listening to Bedpan Banter. And if you found this helpful, make sure you like and subscribe so you don't miss any future episodes. So we'll see you next time in part two. And as always, don't let the bedpans bite.

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