In a diabetic — especially an older adult with type 2 — sugar can climb gradually to very high numbers (sometimes past 600 mg/dL) with severe dehydration that pulls water out of the whole body. This is called hyperosmolar hyperglycaemic state (HHS), and its usual triggers are: infection (urinary or chest), stopped medication, or too little water in the heat.

In short — what to do

  1. Check the sugar now if a meter is available — repeated readings above 400, or "HI", is a real alarm.
  2. Water in frequent sips — water only, no juices or sweetened drinks.
  3. Do not stop insulin or diabetes medication — keep the prescribed doses.
  4. Look for the trigger: fever? burning urine? cough? — and see a doctor today, not tomorrow.

Videos for this topic

Dangerous high sugar creeps in quietly over days

27 seconds

Watch for the trio: extreme thirst, passing urine again and again, and drowsiness or confusion that keeps growing. If they are awake and can drink: check the sugar and give water only, not juice, and never stop diabetes medicine during illness. If they become oddly drowsy or confused, or are vomiting and cannot drink: go to the ER at once.

Watch it on Instagram

Sick and not eating… should insulin stop?

23 seconds

Stopping insulin during illness "because they're barely eating" is the most dangerous mistake; a sick body needs it more, not less. The sick-day rule: check more, drink more water, and never stop the medication.

Caring for a sick diabetic: the sick-day rule

15 seconds

A sick body needs insulin more, not less. The sick-day rule: check more, drink more water, never stop the medication — and keep the prescribed doses.

Capsule: when the family is aware, high sugar can't creep in

15 seconds

Watch for the trio: thirst that won't go away, passing urine again and again, and growing drowsiness or confusion. Check the sugar at once and give water only, not juice; if they become drowsy, confused or can't drink: go to the ER.

Frequent sips of water and frequent checks — and never stop diabetes medication while ill
Frequent sips of water and frequent checks — and never stop diabetes medication while ill
The full details

The signs — building over days

  • Thirst that won't quench, dry mouth and skin.
  • Lots of urine at first — then less as dehydration deepens.
  • Fatigue and drowsiness growing day after day.
  • Confusion, strange speech, or out-of-character behaviour.
  • And in severe cases: seizure or difficulty waking — coma.

Awake and able to drink?

  1. Check the sugar now if a meter is available — repeated readings above 400, or "HI", is a real alarm.
  2. Water in frequent sips — water only, no juices or sweetened drinks.
  3. Do not stop insulin or diabetes medication — keep the prescribed doses.
  4. Look for the trigger: fever? burning urine? cough? — and see a doctor today, not tomorrow.

Go to the ER immediately if

  • Unusual drowsiness, confusion, or difficulty waking them.
  • Repeated vomiting that prevents drinking, or refusal of fluids.
  • Sugar above 400 that won't come down despite water and medication.
  • Deep rapid breathing or a "fruity" smell on the breath — especially in type 1, this may be diabetic ketoacidosis, faster and more dangerous.
  • Fever with chills — infection is this condition's fuel.

Common mistakes

  • Stopping insulin during illness "because they're barely eating" — the most dangerous mistake; a sick body needs it more, not less.
  • Quenching the thirst with juices and soft drinks — pouring oil on the fire.
  • Unconscious? Never anything in the mouth: recovery position and call 998 immediately.

The sick-day rule

When a diabetic falls ill: check more, drink more water, and never stop the medication. And remember the triad: unquenchable thirst + lots of urine + a clouding mind = ER today, not tomorrow.

This content is for general health education only and is not medical advice. Always seek guidance from a qualified healthcare professional. In an emergency, call 998.

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