Advanced Diabetic and Endocrine Emergencies

1. Insulin is the hinge everything else swings on

Diabetes is a disorder of insulin. So start there.

Insulin's job is to move glucose out of the blood and into your cells. No insulin, and glucose piles up in the blood while the cells starve for fuel anyway. That's the whole disease in one sentence.

Type 1 diabetics make no insulin. Their cells have nothing to let glucose in, so under stress they switch to burning fat instead. Fat breakdown makes ketones, and ketones are acidic. Build up enough of them and you get diabetic ketoacidosis — DKA. Keto is the root you'll see again: ketones, ketoacidosis, ketosis. It always means the fat-burning byproduct.

Type 2 diabetics still make some insulin, usually enough to keep fat-burning suppressed. So under stress they don't make ketones. Instead their glucose climbs and climbs, unopposed, until you get hyperglycemic hyperosmolar syndrome — HHS. No ketones, no acidosis, just an enormous glucose number and catastrophic dehydration.

That's the either/or split for this whole lesson. Insulin present or absent decides which of the two big emergencies you're looking at. But both start the same way underneath. Glucose spills into the urine once the blood level gets high enough. And it pulls water out with it. That's an osmotic gradient — high sugar concentration in the urine drags water out of the body to follow it. So both DKA and HHS are dehydration emergencies at their core. That's why fluid is the field treatment for both.

One more number worth anchoring here: hyperglycemia is a plasma glucose above 200 mg/dL, or a fasting level above 126 mg/dL. Keep that in your pocket — it's not what drives your field treatment, but it's the definition the exam will hand you.