Emergencies: Ketoacidosis, Hyperosmolar State, and Low Blood Sugar

When there's no insulin at all: ketoacidosis

Diabetic ketoacidosis (DKA) is what happens when insulin runs out completely — most often in type 1 diabetes, during illness, or when insulin doses are missed. Without insulin, glucose can't enter cells, so the body thinks it is starving even while sugar piles up in the blood. In a panic, it switches to burning fat for fuel.

Burning fat fast produces acidic byproducts called ketones. As ketones flood the blood, it turns acidic — that's the “acidosis.” The result is a dangerous combination: very high sugar, dehydration from heavy urination, deep rapid breathing (the body blowing off acid), a fruity smell on the breath, vomiting, and eventually drowsiness and coma. DKA is a medical emergency treated in hospital with fluids, insulin, and careful correction of body salts (especially potassium).

Sky-high sugar without ketones: the hyperosmolar state

There is a second high-sugar emergency, usually seen in older adults with type 2 diabetes: the hyperosmolar hyperglycemic state (HHS). Here a little insulin still lingers — enough to block fat-burning, so significant ketones don't form — but not enough to control sugar. Blood glucose climbs to extreme levels (often above 600 mg/dL).

All that sugar drags enormous amounts of water out through the urine (polyuria), leading to profound dehydration. The blood becomes thick and concentrated — “hyperosmolar” — which itself impairs the brain, causing confusion and coma. The hallmark difference from DKA: very high sugar but little or no acidosis. Treatment centers on aggressive rehydration, then insulin.

The opposite danger: blood sugar too low

Hypoglycemia — blood sugar dropping too low (generally below 70 mg/dL) — is the most common acute emergency in *treated* diabetes. It usually comes from too much insulin or certain pills relative to food eaten or activity done. Because the brain runs on glucose, the symptoms come fast: shakiness, sweating, a racing heart, hunger, then confusion, slurred speech, and, if untreated, seizures or loss of consciousness.

Normally the body defends itself with counter-regulatory hormones — glucagon first, then adrenaline and others — which is why the early symptoms feel like an adrenaline rush. But after years of diabetes these defenses can blunt, and warning signs may fade (“hypoglycemia unawareness”), making lows more dangerous.

1. Recognize: if someone with diabetes is suddenly shaky, sweaty, confused, or acting drunk, suspect a low — when in doubt, treat as low.
2. If awake and able to swallow: give about 15 g of fast sugar — juice, glucose tablets, regular soda — wait 15 minutes, recheck, repeat if still low (the “15-15 rule”).
3. If drowsy or unconscious: do NOT force food or drink (choking risk). Use injectable or nasal glucagon if available and call emergency services.

THREE DIABETES EMERGENCIES AT A GLANCE

                 DKA            HHS            HYPOGLYCEMIA
Direction     sugar HIGH      sugar HIGH      sugar LOW
Typical glc   >250 mg/dL      >600 mg/dL      <70 mg/dL
Ketones/acid  YES, acidotic   no / minimal    none
Usual type    type 1          type 2 (older)  any (on meds)
Key clue      fruity breath,  severe          shaky, sweaty,
              deep breathing  dehydration,    confused
                              confusion
First action  ER: fluids +    ER: fluids      fast sugar now;
              insulin + K+    first, insulin  glucagon if out