Differentiating between hypoglycemia, DKA, and HHS in emergency settings

September 11, 2025

Melissa Evans, CVT, LVT, VTS (ECC), discusses signs of hypoglycemia, diabetic ketoacidosis, and hyperglycemic hyperosmolar syndrome.

In this clip, Melissa Evans, CVT, LVT, VTS (ECC), owner and founder of Melissa Evans, VTS (ECC): Veterinary Nurse Consulting, talks about clinical signs that can help veterinary professionals quickly differentiate between hypoglycemia, diabetic ketoacidosis (DKA), and hyperglycemic hyperosmolar syndrome (HHS) when a patient with diabetes presents to the emergency department. She explains that differentiating between DKA and HHS can be challenging due to similar clinical signs. Patients with HHS, she explains, may present with lethargy, mental dullness, and, in extreme cases, coma. Still, Evans emphasizes that the only way to truly differentiate between the 2 conditions is to analyze the patient’s blood values and to do calculations to confirm whether the patient is experiencing HHS. Signs of hypoglycemia, meanwhile, include anorexia, lethargy, unresponsiveness, immobility, seizures (including facial seizures), and twitching.

Related: Identifying diabetic emergencies

Below is a transcript of the video, which has been lightly edited for improved clarity.

Melissa Evans, CVT, LVT, VTS (ECC): Usually, with hypoglycemia, we'll have reports from the owners that [the patients] haven’t been eating or that they are a known [cat with diabetes] who may have gotten extra insulin. Clinical signs [of hypoglycemia] are usually lethargy; they may not be moving at all [or] might not be responsive to things. Sometimes, they can have seizures, or a lot of owners say they start twitching; they have little focal facial seizures that [are] very common in hypoglycemia.

In DKA and HHS, it's a little harder to differentiate. The symptoms are very similar. Usually, with [HHS], the patients are much more lethargic. They're very dull mentally. Sometimes they're even obtunded. If it's really bad, they can be in a coma, but the only way to really differentiate between the 2 is to do some math and to look at their blood values, and then calculate [whether] they are hyperosmolar.