Sick days: the insulin does not stop

Being sick with type 1 diabetes — a cold, the flu, a stomach bug, an infection — changes the rules. This page explains why insulin keeps going when food stops, what to keep doing, which medications usually pause, and what to have ready before you ever need it.

Why the insulin does not stop

Illness raises your insulin needs even when you are eating nothing at all. Stopping insulin because no food is going in is the single most common route into ketoacidosis.

What usually pauses

While you are dehydrated, some medications are usually paused, because they strain the kidneys when you are dry:

• SGLT2 inhibitors
• ACE inhibitors and ARBs
• diuretics
• metformin
• anti-inflammatories like ibuprofen

Your own list will depend on what you take. Get your personal hold list from your pharmacist, on paper, before you are ever ill enough to need it — and do not stop or restart anything without that list or your team's advice.

Carbs in liquid form

If solids won't stay down, carbohydrate can come from:

• regular pop
• juice
• sports drink
• ice pops
• sweet tea

Plus something salty — broth or a rehydration solution.

The box, ready in advance

The written plan matters because the person reading it may be a parent or partner while the person with diabetes is too unwell to think. Ask your diabetes team for one, and keep it in the box.

A pump failure is its own sick day

With a pump, there is no long-acting insulin depot underneath. If the pump stops delivering, ketones climb fast. Treat a pump failure with the same urgency as illness, and follow your team's plan for switching to injections.

When to go in

Call 911 if the person is unconscious, seizing, or has ketones with vomiting. Nobody has ever been in trouble for arriving at an emergency department with ketones.

More on sick-day hold lists and the medications that affect glucose is in the Medications section.