Sick days with a child who has Type 1 diabetes are a different category of illness management than with other children. The same cold that means an extra day of rest and a box of tissues for most children can trigger a dangerous blood sugar spiral in a child with T1D — and the instincts that feel right (giving less insulin because they’re not eating, waiting to see if things improve) are often exactly wrong.
This guide is the sick day protocol explanation your discharge packet should have included.
Why Illness Makes Blood Sugar Skyrocket
The counterintuitive truth of sick day management: your child will almost certainly need more insulin when sick, not less — even if they’re barely eating.
Here’s why. When the body detects infection, injury, or illness, it mounts a stress response by releasing cortisol, glucagon, adrenaline, and growth hormone. These counterregulatory hormones serve an evolutionary purpose — they release stored glucose to fuel the immune response. In a person without diabetes, the pancreas automatically increases insulin secretion to match.
In Type 1 diabetes, that automatic response doesn’t happen. Stress hormones dump glucose into the bloodstream, but there’s no insulin increase to absorb it. The result: blood sugar climbs, sometimes dramatically, even when your child has eaten nothing all day.
A 2013 study in the Journal of Clinical Endocrinology & Metabolism documented cortisol levels in children with T1D during illness that were significantly higher than in healthy controls — and these levels correlated directly with degree of hyperglycemia and ketone production.
This is the most dangerous sick-day mistake. Reducing or stopping basal insulin when your child isn’t eating — because it seems logical — removes the baseline insulin that prevents ketone production. Without basal insulin, the body starts breaking down fat for fuel, producing ketones. This is how DKA develops. Keep basal insulin running unless your team has given explicit guidance to do otherwise.
The Two Types of Sick Days
Sick day management differs significantly depending on whether vomiting is involved.
Type 1: Illness without vomiting (fever, cold, ear infection, UTI)
This is more manageable. Your child can take oral fluids, eat to some degree, and keep medications down.
What to do:
- Check blood sugar every 2 hours, not just at mealtimes
- Check ketones every 2–4 hours if blood sugar is above 250 mg/dL
- Continue all insulin (basal and scheduled doses)
- Increase correction frequency per your team’s sick-day scale
- Push fluids aggressively — dehydration worsens hyperglycemia and accelerates ketone production
- If appetite is reduced, offer small amounts of easily digestible carbohydrates (crackers, toast, applesauce, broth with noodles) rather than full meals, and adjust bolus accordingly
Target during illness: Most teams recommend a slightly wider acceptable range during illness — 100–200 mg/dL rather than 70–180 mg/dL — acknowledging that perfect control isn’t realistic when the body is fighting infection.
Type 2: Illness with vomiting (stomach bugs, gastroenteritis)
This is the high-risk scenario. A child who cannot keep fluids or food down cannot absorb oral glucose for low treatment. Dehydration accelerates ketone production. And the stomach bug itself is raising blood sugar through stress hormones while the child can eat nothing.
Immediate questions:
- What is the blood sugar right now?
- What are the ketones?
- Can your child keep small sips of fluid down?
The sip protocol: If your child is vomiting, try 5–10ml of clear fluid (water, electrolyte drink, flat ginger ale, broth) every 5 minutes. This is often enough to maintain hydration even when larger amounts are immediately rejected. Keep the blood sugar and ketone data coming in while you try.
The decision tree for vomiting + high blood sugar:
| Situation | Action |
|---|---|
| BG high, ketones trace/small, keeping sips down | Home management, call team for correction guidance |
| BG high, ketones moderate, keeping sips down | Call team immediately — may need to go in |
| BG high, ketones large, or can’t keep any fluid down | Go to ER — IV fluids and IV insulin needed |
| BG low + vomiting (can’t treat with oral glucose) | Go to ER or use glucagon — this is urgent |
If blood sugar drops below 70 mg/dL and your child cannot keep juice or glucose tablets down, you cannot treat the low at home. Use nasal glucagon (Baqsimi) or injectable glucagon immediately and call 911. A child who is hypoglycemic and vomiting cannot wait.
The Sick-Day Insulin Adjustment Principles
Your endocrinology team should give you a written sick-day protocol with specific dose adjustments for your child. If you don’t have one, request it at your next appointment — before you need it.
General principles your team will build from:
Correction doses: During illness, most teams increase correction dose frequency (every 2–3 hours rather than every 3–4 hours) and sometimes increase the correction factor itself (a larger dose for the same elevated reading) because insulin sensitivity decreases during illness.
Pump users: Many teams recommend increasing basal rate by 10–20% across the board during illness (or using a temporary basal increase on the pump). Some closed-loop systems will automatically increase delivery in response to sustained highs — but the algorithm has limits, and a sick-day manual increase often helps.
MDI users: The adjustment is harder. Options include increasing the long-acting dose (if illness lasts more than 24 hours), increasing correction frequency, or using sliding-scale correction guidelines your team provides in advance.
Medicines to Watch Out For
Several common over-the-counter medications affect blood sugar:
| Medication | Effect on Blood Sugar | Note |
|---|---|---|
| Most cough syrups | Raises (contain sucrose or glucose syrup) | Use sugar-free versions when possible |
| Prednisone / oral steroids | Significant raise — sometimes +100-200 mg/dL | Contact your team immediately when prescribed; dose adjustment is always needed |
| Ibuprofen (Advil, Motrin) | Minimal direct effect | Generally safe; reduces fever which itself raises BG |
| Acetaminophen (Tylenol) | Interferes with some CGM readings (Dexcom) | Causes falsely high CGM readings; use fingerstick when on high-dose acetaminophen |
| Decongestants (pseudoephedrine) | Raises | Use with caution; contact team if BG uncontrollable |
| Antibiotics | Variable | Some affect gut flora, which can affect glucose absorption — watch closely |
Ask your pharmacist for sugar-free formulations of any liquid medication when your child has T1D. They exist for most common products and are medically indicated — not an optional upgrade.
What to Keep in Your Sick-Day Kit
Prepare this before you need it:
- Blood ketone meter and strips (more accurate than urine strips)
- Electrolyte drink (Pedialyte or equivalent) — sugar-containing fluids appropriate for treating mild lows during illness
- Sugar-free electrolyte drink — for hydration when blood sugar is high
- Glucagon kit (nasal Baqsimi ideally) — essential if vomiting occurs with a low
- Sugar-free versions of common medications — cough syrup, decongestant, antihistamine
- Your written sick-day protocol from your team
- Your team’s after-hours phone number — written down, not just saved in your phone
Fever-Specific Considerations
Fever itself raises blood sugar through cortisol and growth hormone release. Each degree of temperature above normal adds approximately 10–20mg/dL to blood sugar in many children — this is a rough estimate, but it helps explain why a 103°F fever produces such dramatically elevated readings even when your child is sleeping and hasn’t eaten.
Treating the fever (with acetaminophen or ibuprofen, as your pediatrician recommends) often partially resolves blood sugar elevation. If readings are very high, confirm with a fingerstick if on Dexcom and taking acetaminophen — high-dose acetaminophen interferes with the Dexcom G7’s sensor chemistry and produces falsely elevated CGM readings.
When to Call Your Team vs. When to Go Straight to the ER
Call your team’s after-hours line:
- Blood sugar above 250 with small/moderate ketones and your child can keep fluids down
- Blood sugar below 70 with vomiting but child is conscious and you have glucagon
- Illness lasting more than 24 hours with sustained blood sugar elevation
- Any situation where you’re not sure what adjustment to make
Go to the ER without calling first:
- Large/high ketones, especially with vomiting
- Blood sugar above 300 for more than 2 hours despite corrections
- Your child is confused, lethargic, or difficult to rouse
- Rapid or labored breathing (Kussmaul breathing — sign of DKA)
- Fruity or acetone-smell breath
- Blood sugar below 70 with vomiting and no glucagon, or glucagon didn’t work
- Your child is an infant or toddler — the margin for error is smaller, err toward the ER earlier
The Day After: When Does It Get Back to Normal?
Most children will have elevated blood sugar and increased insulin requirements for 24–48 hours after they start feeling better. The stress response lingers even when the acute infection resolves. Don’t rush back to normal doses — maintain closer monitoring and slightly increased correction readiness until blood sugar patterns return to your child’s baseline for two consecutive days.