By Katerina | Double T1D Mom | Updated March 2026
A cold is not just a cold when your child has Type 1 Diabetes.
A stomach bug is not just a stomach bug. The flu is not just the flu. Every illness your child gets comes with a second, invisible layer — unpredictable blood sugar, rising ketones, and the constant threat of a trip to the ER.
In 21 years of managing T1D in two children, I’ve navigated dozens of sick days — from simple runny noses to terrifying stomach viruses where my child couldn’t keep water down. I’ve sat in emergency rooms watching IV fluids drip. I’ve checked ketones at 4 AM while holding a vomiting child.
Here’s everything I’ve learned about keeping a sick T1D child safe at home — and knowing when home isn’t enough.
Why Illness Affects Blood Sugar
When your child gets sick, their body releases stress hormones — cortisol, adrenaline, glucagon — to fight the infection. These hormones also tell the liver to dump extra glucose into the bloodstream. The result: blood sugar goes up, even if your child isn’t eating.
This is the opposite of what most parents expect. You’d think a sick child who isn’t eating would go low. But with T1D, illness usually means highs — stubborn, hard-to-correct highs that can last for days.
The danger: sustained high blood sugar + illness = ketones. And ketones, if left unchecked, can lead to DKA (Diabetic Ketoacidosis) — a life-threatening emergency.
There are exceptions. Some illnesses — especially stomach bugs with vomiting — can cause lows because the child can’t keep food down but the insulin is still working. This makes sick days a constant balancing act between highs and lows.
The Sick Day Checklist (Print This)
The moment your child shows signs of illness, start this protocol:
Check Blood Sugar Every 2–3 Hours
Even with a CGM, do manual finger prick checks during illness — CGM accuracy can decrease when a child is dehydrated. Check every 2–3 hours around the clock, including overnight.
If blood sugar is consistently above 250 mg/dL and not responding to corrections — this is a red flag.
Check Ketones Every 2–4 Hours
This is the step most parents skip — and it’s the most important one during illness.
Use blood ketone strips (more accurate than urine strips) if available. Your endo should have prescribed a blood ketone meter — if they haven’t, ask for one now, before your child gets sick.
Ketone levels:
- Below 0.6 mmol/L — negative, normal
- 0.6–1.0 mmol/L — trace, monitor closely, increase fluids
- 1.0–1.5 mmol/L — moderate, call your endocrinologist
- 1.5–3.0 mmol/L — high, call your endo immediately, prepare for possible ER visit
- Above 3.0 mmol/L — go to the ER now
If you only have urine ketone strips: trace or small = monitor; moderate = call endo; large = ER.
Push Fluids
Dehydration makes everything worse — it makes blood sugar harder to control and accelerates ketone buildup. Your child needs to drink constantly during illness.
If blood sugar is HIGH (above 200): sugar-free fluids — water, sugar-free Pedialyte, sugar-free popsicles, broth, diet Gatorade.
If blood sugar is LOW or NORMAL (below 150): regular fluids with sugar — regular Gatorade, juice, regular Pedialyte, flat ginger ale, popsicles. This serves double duty — hydration and glucose.
Minimum fluid goal: at least 1 cup (8 oz) per hour for school-age children. Smaller amounts more frequently for toddlers.
My trick for a child who won’t drink: frozen Pedialyte popsicles, ice chips, and letting them choose a “special” cup or straw. During our worst sick days, I used a medicine syringe to give my son 5 mL of fluid every few minutes when he couldn’t handle more.
Never Stop Insulin
This is the most critical rule: NEVER stop giving insulin during illness, even if your child is not eating.
Your child needs insulin to survive — illness or not. Without insulin, the body starts burning fat for energy, producing ketones, and spiraling toward DKA.
- Basal insulin (long-acting injection or pump basal): continue as normal. Your endo may advise increasing the rate by 10–20% during illness.
- Bolus insulin (for food): adjust based on what they’re eating, but don’t skip meals entirely — even small amounts of carbs with corresponding insulin help prevent ketones.
- Correction doses: you may need more frequent and larger corrections during illness. Follow your endo’s sick day correction formula.
If your child is on Omnipod 5 or another automated system, the pump will try to increase insulin delivery automatically for highs — but during illness, the algorithm may not be aggressive enough. Be prepared to give manual correction boluses on top of what the pump delivers.
Sick Day Scenarios: What to Do
Scenario 1: Cold or Respiratory Infection (Blood Sugar Trending High)
This is the most common sick day. Your child has a cold, cough, or sore throat. They’re eating less but blood sugar is running higher than normal.
Action plan:
- Check blood sugar every 2–3 hours
- Check ketones every 4 hours
- Increase fluid intake
- Give correction doses per your sick day protocol
- Continue basal insulin (consider 10–20% increase if your endo recommends it)
- Avoid cough syrups and medications with sugar — check labels for “sugar-free” versions
- Call your endo if: blood sugar stays above 300 despite corrections, ketones appear, or the illness lasts more than 2 days
Scenario 2: Stomach Bug with Vomiting (Blood Sugar Dropping)
This is the scary one. Your child is vomiting and can’t keep food or liquids down. Blood sugar may be dropping because there’s no food coming in but insulin is still active.
Action plan:
- Check blood sugar every 1–2 hours (more frequently than usual)
- Check ketones every 2 hours (vomiting + T1D = high ketone risk even with normal blood sugar)
- Small sips of sugar-containing fluids: flat ginger ale, regular Pedialyte, juice diluted with water — every 5–10 minutes
- Reduce bolus insulin — no bolus for food they’re not eating
- Consider reducing basal by 20–30% if blood sugar is below 150 and dropping (only with endo guidance)
- If on a pump, you can set a temporary basal reduction
- Call your endo if: child vomits more than 2–3 times, can’t keep any fluids down for 2+ hours, blood sugar below 70, or any ketones present
- Go to the ER if: child can’t keep fluids down for 4+ hours, ketones above 1.5, blood sugar is persistently below 70 despite attempts to treat, child is lethargic or confused
When my son had a stomach virus at age 6, his blood sugar dropped to 55 while he was vomiting. He couldn’t drink juice without throwing it up. That was the moment we went to the ER. They gave him IV dextrose and fluids, stabilized him within hours, and we went home the same day. I learned: don’t wait too long hoping it will get better. If they can’t keep fluids down, go.
Scenario 3: Fever (Blood Sugar Roller Coaster)
Fever can cause both highs and lows — highs from stress hormones, lows from not eating. Blood sugar may swing wildly.
Action plan:
- Check blood sugar every 2 hours
- Check ketones every 4 hours
- Treat fever with acetaminophen (Tylenol) or ibuprofen (Advil) — check that they’re sugar-free
- Offer easy-to-eat foods: crackers, toast, soup, applesauce
- Extra fluids
- Be prepared to adjust insulin in both directions — more for highs, less for lows
- Call endo if fever persists above 101°F for more than 24 hours with blood sugar instability
Scenario 4: Diarrhea Without Vomiting
Diarrhea alone is less dangerous than vomiting (because the child can still drink and eat), but it causes dehydration, which affects blood sugar.
Action plan:
- Push electrolyte fluids (Pedialyte, Gatorade)
- Bland foods: bananas, rice, toast, applesauce (the BRAT diet)
- Check blood sugar every 3 hours
- Check ketones every 4 hours
- Monitor for dehydration: dry lips, no tears, dark urine, sunken eyes
- Call endo if dehydration signs appear or blood sugar becomes unstable
When to Go to the Emergency Room
Go to the ER immediately if:
- Ketones above 1.5 mmol/L (blood) or large (urine) that don’t come down with fluids and insulin
- Vomiting that won’t stop — can’t keep fluids down for 4+ hours
- Blood sugar below 54 that doesn’t respond to treatment
- Blood sugar above 400 that doesn’t respond to correction doses
- Your child is confused, extremely sleepy, or difficult to wake
- Rapid or labored breathing (Kussmaul breathing — a sign of DKA)
- Fruity smell on breath (another DKA sign)
- Your gut says something is wrong — trust it
At the ER, tell them immediately: “My child has Type 1 Diabetes. I’m concerned about DKA.” This should trigger immediate blood work and IV fluids. Bring your child’s insulin, pump, CGM receiver, and your phone with CGM data — the ER team will want to see recent blood sugar trends.
[Related: → DKA Warning Signs in Children — When to Call 911]
Sick Day Medicine Cabinet
Keep these on hand at all times — don’t wait until your child is sick to buy them:
- Sugar-free acetaminophen (Tylenol) — for fever and pain
- Sugar-free ibuprofen (Advil) — alternate with Tylenol for high fevers
- Pedialyte (regular and sugar-free) — for hydration
- Blood ketone meter and strips — more accurate than urine strips
- Anti-nausea medication (Zofran/ondansetron) — ask your endo for a prescription to keep on hand. This can stop vomiting long enough for your child to drink fluids and avoid the ER.
- Glucose gel or honey — for treating lows in a child who can’t swallow tablets
- Glucagon (Baqsimi nasal or Gvoke) — emergency treatment for severe lows
- Popsicles — both sugar-free and regular
- Crackers, broth, applesauce — bland sick-day foods
Pro tip from 21 years: Ask your endocrinologist for a prescription for Zofran (ondansetron) to keep at home. This anti-nausea medication has saved us multiple ER trips. When my son starts vomiting, I give Zofran first — if it stops the vomiting, he can drink fluids, and we can manage at home. If it doesn’t stop the vomiting, we go to the ER. Having this one medication at home is a game-changer.
Creating a Sick Day Plan With Your Endo
Don’t wait for illness to figure out your plan. At your next endocrinologist appointment, ask these questions:
- What is our sick day correction dose? (It’s usually higher than the regular correction dose)
- When should I increase basal insulin, and by how much?
- When should I decrease basal insulin?
- At what ketone level should I call you?
- At what ketone level should I go to the ER?
- Can you prescribe Zofran to keep at home?
- Can you prescribe a blood ketone meter?
Write the answers down and tape them to the inside of your diabetes supply cabinet. When your child is sick at 2 AM, you won’t be able to think clearly. The plan should be in front of you.
Frequently Asked Questions
Should I keep my T1D child home from school when they’re sick? Follow the same guidelines as for any child — fever, vomiting, or too sick to participate. But with T1D, add this rule: if blood sugar is so unstable that it requires checks every 1–2 hours, keep them home. Most schools can’t provide that level of monitoring.
Can illness cause a new T1D diagnosis to look different? Yes. Illness can trigger DKA in a newly diagnosed child faster than in a child who’s been managing T1D for years. If your child was recently diagnosed, be extra vigilant during illness and call your endo early.
My child’s blood sugar is high but they have no ketones. Is that okay? High blood sugar without ketones is manageable at home with extra insulin and fluids. Monitor ketones every 2–4 hours because they can appear quickly. If blood sugar stays above 300 for more than 6 hours despite corrections, call your endo.
Can I give my child regular cough medicine? Check the label. Many children’s medicines contain sugar, which can spike blood sugar. Look for “sugar-free” or “diabetic-friendly” versions. Always check with your pharmacist if unsure.
How soon after illness does blood sugar return to normal? Usually 1–3 days after symptoms resolve. Some children run slightly higher for up to a week after illness. Insulin sensitivity may also increase after illness, causing unexpected lows once the stress hormones subside — watch for this.
Should I change insulin pump sites more often during illness? If blood sugar isn’t responding to corrections, a bad site could be the cause. Change the site and give a correction by injection (not through the pump) to rule out a site issue. We’ve had situations where what looked like illness-related highs was actually a failed pump site — changing it fixed everything in an hour.
→ New to T1D? Start here: What to Do After Your Child’s Diagnosis
→ Get the Free T1D Parent Starter Kit (PDF)
This article reflects 21 years of personal experience managing illness in two children with Type 1 Diabetes. Sick day protocols vary by child. Always follow your endocrinologist’s specific sick day instructions. In an emergency, call 911. Read my full Medical Disclaimer.