You Will Never Mix Up DKA And HHS Again with Nurse Mike

DKA vs HHS can feel like a blur when you’re studying, but the body tells a clear story if you know what to listen for. I’m Nurse Mike, and I’m breaking these two diabetic emergencies into a simple framework you can use under pressure on exams and in real clinical care: speed of onset, what’s happening at the cellular level, and the few “can’t miss” signs and labs that separate them.

We start with the core pathophysiology. DKA is a no-insulin problem that pushes the body into fat burning, ketone production, and metabolic acidosis, which shows up as a low pH, low bicarbonate, and a high anion gap. HHS is a some-insulin problem where ketones don’t build up, but glucose climbs to extreme levels, causing osmotic diuresis, severe dehydration, high serum osmolality, and more dramatic neurologic changes like confusion. You’ll hear exactly why DKA tends to be fast while HHS usually develops over days, and how that timeline becomes a major NCLEX clue.

Then we get practical: hallmark symptoms (abdominal pain and Kussmaul respirations in DKA), the lab patterns you can spot quickly, and the treatment priorities that show up in nursing questions. We walk through fluids first (0.9% normal saline), IV regular insulin with careful monitoring, and the potassium rule that can change everything: if K+ is too low, you correct it before insulin to protect the heart. We also tackle priority scenarios using the “who is most unstable” mindset, where acidosis and airway concerns can outrank mental status changes.

If this helps you, subscribe to Bedpan Banter, share the episode with a classmate, and leave a review so more nursing students can find it. What part of DKA vs HHS trips you up most: symptoms, labs, or treatment order?

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Transcript

Welcome And What You’ll Learn

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We got a code brown. Welcome to Bedpan Banter. With me, Nurse Mike, the Dead 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 tested, most misunderstood topics in nursing school and on the NCLEX. We're talking about DKA diabetic ketoacidosis versus HHS, hyperglycemic, hyperosmolar syndrome. Woo! All right, guys, by the end of this episode, these two will be crystal clear, organized in your brain, and locked in for test day. We're gonna combine memory tricks, pathophysiology, subtle symptom differences, lab interpretation, and how the current NCLEX exam

Core Patho Fast Vs Slow

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thinks. So let's get into the core patho, fast versus slow. Now, DKA is when there's no insulin. So the body burns fat for fuel, which makes ketones, and that becomes dangerously acidic in the body. HHS, on the other hand, is when blood sugar gets extremely high. So that's why I say HHS is the higher blood sugar. The body becomes severely dehydrated and the brain starts to shut down. But here's the key point without that acid buildup. Now the first distinction that most students miss is that DKA is fast and HHS is slow. So DKA simply think it develops rapidly, sometimes within hours. And HHS develops gradually, often over a few days. That matters because the NCLEX may describe a timeline in the case example. So here's a memory trick that helps you to remember the type of diabetes that it's associated with. Think D comes first in the alphabet before H. So DKA is for type 1 diabetics, and HHS is for type 2. Again, H comes second in the alphabet. And DKA has no insulin, HHS has some insulin, and that some insulin is the key difference. So for a DKA pathorefresher, no insulin means that glucose can't enter the cell. This causes the body to burn fat. Then ketones form, resulting in metabolic acidosis. So the pH then drops below 7.35, meaning an acidotic state. And bicarb drops below 18, often below 15. And here's another quick point the anion gap is elevated in DKA. So if you see the words anion gap or metabolic acidosis, that's a huge indicator of DKA. Now let's talk about HHS patho and let's expand it more. So for HHS patients, they still produce small amounts of insulin, and this is enough to prevent ketosis, but not enough to prevent extreme hyperglycemia, that high sugar. Glucose can be over 600, 800, even over a thousand plus. This extremely high level of glucose causes severe osmotic diuresis, massive water loss leading to dehydration, severe hyperosmolarity, aka highly concentrated blood, you can simply think thick sugary blood, often a value greater than 320. So that high serum osmolarity is what causes neurological changes. Because simply think, cells shrink, including the brain cells. And that's why confusion is more severe in HHS than DKA.

Key Signs That Separate Them

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Now, before we dive deeper into the differences, we know that both conditions have four things: polyuria, which means that we're peeing a lot, polydipsia, that chronic thirst, dehydration, and tachycardia, that high heart rate. But here are the big differences between them. DKA has a rapid onset, and you'll often see it with abdominal pain. So I'd be sure to write that one down. That one's a huge test tip. In HHS, we don't typically see abdominal pain. So think DKA causes that metabolic acidosis, the A right there, which triggers inflammation, also nerve stimulation, and GI issues like delayed gastric emptying. Next is cousmol respirations, aka air hunger. So these are deep, rapid, and labored breathing patterns, which occurs as a mechanism to compensate for that severe metabolic acidosis. Next, you're gonna notice for your breath due to those high ketone levels. And remember, this is most common in type 1 diabetics and often occurs in younger age or newly diagnosed diabetics. A key fact is that DKA is sometimes the first sign of type 1 diabetes. So on the NCLEX, if the question says that you have a teenager with a new diagnosis, think that it's DKA over HHS. Okay, now switching gears to HHS, you want to write these down. This one has a gradual onset. And remember that those sugar levels are extremely high, higher than DKA, which causes that hyperosmolarity, that thick syrupy blood, and severe neurological changes. So you can think confusion or some type of disorientation. Now, unlike DKA, we won't have those cousin respirations or abdominal pain. And usually we will see this in older adults with infection. Now, HHS also will cause severe dehydration. So you're gonna notice very dry mucous membranes and hypotension, that low blood pressure. Now, another exam tip because HHS patients are often older, they often tolerate dehydration very poorly. So mortality rate is actually higher in HHS than DKA due to this

Labs That Scream DKA Or HHS

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fact. Now let's get into labs, the fun part. Luckily, all the normal ranges for labs will be provided for you on the NCLEX. So you don't have to sweat that. But in your nursing career, it's always good to have a strong foundational knowledge and understanding of lab values. For DKA and HHS, the labs have indicators that clearly differentiate between one and the other. So here are the DKA labs. Glucose is typically greater than 250, pH is less than 7.35, so it's acidic or puts the body in acidosis. Bicarb is less than 18, also a big indicator of acidosis. Here's a big one here. Ketones. They are positive. Remember, in DKA there's no insulin. So the body burns fat for fuel, which makes ketones. Another key indicator is the anion gap. This one's going to be high, which indicates that high acidity in DKA. Remember, think A for acid in diabetic ketoacidosis. Now, potassium is initially high in the beginning, but remember, the total body has low potassium. So that's where we use the memory trick, DKA. A is for add the potassium, because eventually it's going to be low. Now for HHS, here are the labs. Be sure to write these down. Glucose will be higher. HHS think higher sugar, so over 600, much higher than DKA. Now the pH is normal, so patients won't be in acidosis. Bicarb is going to be normal, indicating the same thing, not in acidosis. And seramos molarity is going to be greater than 320. So this is high. And that's why we think we have super concentrated blood, or what I like to call thick syrupy blood, where the blood is kind of turned into mud. Now, very lastly, BUN and creatinine are going to be elevated, our two kidney labs. This is due to that dehydration. So our organs are going to be struggling big time now. And always remember, creatinine over 1.3 is bad kidney. And urine output 30 ml per hour or less, this means the kidneys are in distress.

Treatment Priorities Fluids First

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All right, now the easier part to remember the treatments, because they're quite similar. So for both DKA and HHS, the patient will get three things fluid, insulin, and electrolyte correction. The main point is that priority matters. You always want to do fluids first. So write this down. You want to start with 0.9% normal saline. In HHS, that aggressive hydration alone can significantly lower the glucose. Because again, think dilution will improve the circulation and even kidney perfusion. So if the question asks, what intervention will most quickly improve the mental status in HHS, the answer is always going to be IV fluids. And remember, normal saline. Now for the insulin strategy. Remember this, we only do regular insulin via IV. So you can simply think regular insulin goes right in the vein. And hourly glucose checks to continuously monitor that glucose. We want to slow the reduction until around the 200 range in DKA or 250 to 300 range in HHS. Now for DKA, we must clear the ketones, not just lower the sugar. So we would want to continue insulin and then add dextrose to prevent that hypoglycemia while continuing. I always like to tell students that it's kind of like landing a plane. You don't want to crash your patient into hypoglycemia by dropping that sugar too low. So remember, we want to stabilize it out. And that's why we add the sugar. So remember that dextrose is to prevent that hypoglycemia while we lower that blood sugar. And that is the main difference here. Because with DKA, insulin will be continued until the anion gap closes, not just when glucose gets normalized, like with HHS.

Potassium Rules Before Insulin

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All right, now a quick note on potassium specifically. This electrolyte is always so important because as we know, potassium pumps the heart. That's why I always say potassium is priority. So before we start insulin for DKA and HHS treatment, look at the value here. If potassium is lower, let's say less than 3.3, well, we hold the insulin and correct potassium first. Because remember, potassium is priority as it pumps the heart. Now, if we give insulin when the patient is already hypochalemic, that low potassium, this will drive potassium into the cells, worsening that hypochalemia. Because remember, insulin puts sugar and potassium into the cell.

NCLEX Priority Scenarios

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Now, before we wrap up, let's see if you can recognize some priority-focused questions. Remember, the current 2026 NCLEX tests on recognition of instability in our patients. So you always want to prioritize the most unstable patient. I just say who dies first or who gets harmed first. So for example, which patient out of these two is the highest priority? Is it patient A? The glucose is 480. We have deep, rapid respirations, and the pH is 7.21. Or would it be patient B? Glucose is 720, the patient is confused, and we have a normal pH. Now go ahead and take a minute and give yourself a few seconds to think about this. Think it through. But always ask yourself: is acidosis occurring in one of these patients? Or is this more or less important than having a stable pH or mental status changes? So drumroll, please. The correct answer here would be patient A. The patient with the glucose at 480 with a deep rapid respirations, and here's the trick here, a pH of 7.21. This is because acidosis is very deadly. It affects breathing immediately. And airway is always a higher priority than neurochanges here. But this is not saying that mental status change is not important. We are simply thinking who dies first or who would I see first? Or you can always think, who would I stabilize first? Now, here's another scenario. Let's say we have a patient with HHS and they have a glucose of 800, but they have a stable airway and they're breathing perfectly. What do you anticipate first for treatment? Would it be fluids, insulin, or electrolyte correction? So give yourself a few seconds to think this through. Remember, in this scenario, for both DKA and HHS, fluids are usually first. But in case you forgot that on an exam, think what is happening to my patient here. Because we know this is HHS, we know that the patient is not in acidosis, but they are severely dehydrated. This would indicate aggressive IV fluids as the first step for treatment. Remember, think the H in HHS, they have to get hydration first, because that's the first letter. Although insulin can help with this high sugar, fluids can also help with lowering those glucose levels and treating the dehydration.

Practice Links And Closing

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We have some free practice questions specifically on DKA and HHS. And we have a link to those in the description so that you can test your knowledge. Or if you want to change things up, you can head over to SimpleNursing.com to sign up for a free trial and access lots of additional topics. As always, thank you so much for listening to Bedpan Banter. And if you found this helpful, make sure you like, share, and subscribe so you don't miss any future episodes. We'll see you guys next time. And as always, don't let the bedpans bite.

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