SICK DAY MANAGEMENT
How to keep blood sugar steady — and yourself safe — when you’re not feeling well.
Even a regular cold or stomach bug can throw your blood sugar off. This chapter walks you through what changes inside your body when you’re sick, the simple steps that keep you safe, what belongs in a sick-day kit, and the warning signs that mean it’s time to call for help.
Why being sick is different
When your body is fighting an illness, it works harder — and that affects blood sugar in ways you can’t always predict.
⚡ A sick body…
• Needs more energy to fight the infection.
• Releases a stress hormone called cortisol, which pushes blood sugar up.
• Can lose fluid quickly through fever, vomiting, or diarrhea — making dehydration a real risk.
The result: blood sugar becomes harder to manage, even if you’re eating less than usual.
What to do when you’re sick
A few simple habits cover most sick days. Adjust them with your medical team to fit your treatment plan.
🩸 Check more often
- Test your blood sugar every 2–4 hours when sick — your team may want it more often if you’re particularly unwell or your numbers are unstable.
- Check overnight too if you’re particularly sick or your numbers are unstable.
💧 Stay hydrated
- Sip fluids every 10–15 minutes, especially if you can’t keep food or drink down.
- Avoid caffeine — it can worsen dehydration.
- For hydration:
- If your blood sugar is below 200 mg/dL and you aren’t eating, drinks with carbs (regular juice, regular soda) can help prevent lows.
- If your blood sugar is above 200 mg/dL, choose sugar-free drinks so hydration doesn’t push your blood sugar higher.
- Important: hydration isn’t a substitute for insulin. If your blood sugar is high or you have ketones, follow your sick-day plan for correction doses — fluids alone won’t bring it down.
🍲 Try to eat
- Keep simple carbs handy:
- If your blood sugar is low or dropping, fast carbs help (regular soda, juice, jello, popsicles).
- If your blood sugar is steady or you just need to keep something down, slower carbs are gentler (crackers, toast).
- Eat small amounts often instead of full meals.
🧪 Check ketones
- Use urine strips or a meter that measures blood ketones.
- When you’re sick, check ketones routinely — they can rise even when your blood sugar looks normal. Most teams recommend checking with each illness, especially if your blood sugar is above 240 mg/dL, you’ve missed an insulin dose, or you don’t feel well.
- If you have type 1 diabetes, watch carefully for signs of diabetic ketoacidosis (DKA), a serious complication that can develop during illness — see Recognizing Highs, Lows & Emergencies for the warning signs.
📱 Tell someone
- Let a family member, friend, or housemate know you’re unwell so they can check in.
- This matters even more if you live alone or will be on your own for several hours.
Insulin treatment when sick
Don’t wait until you’re sick to figure out the plan. Talk with your medical team in advance so you have a clear sick-day guide ready to follow.
👩⚕️ Your medical team should
• Explain the signs and symptoms to watch for.
• Tell you when to seek urgent medical care.
• Spell out what treatment changes are needed — for example, when (and how much) extra correction insulin to give, and how to adjust doses based on your blood sugar and ketone levels.
🔗 Need a refresher on correction doses?
The math behind a correction dose, plus how to handle a low, is covered in Managing Highs & Lows.
Your sick-day kit
Pack it once and keep it where you can grab it — at home, at school, and in your bag when you travel.
📋 Your plan
- A written sick-day action plan from your medical team
- Emergency contact numbers
🩸 Monitoring supplies
- Blood glucose meter (ideally one that also reads ketones)
- Glucose test strips
- Urine ketone strips as a backup
💉 Medication
- Glucagon (HypoKit) for severe lows — used by a family member or friend if you can’t safely take sugar by mouth.
- Spare insulin pens or vials
🔋 Extras
- Spare batteries for your meter or pump
- Replacement pump or CGM parts (infusion sets, sensors)
- Glucose tabs or gels for quick fixes
Red flags — call your doctor right away
Most sick days can be managed at home, but a few signs mean you need help fast.
🚨 Get medical help if:
- You can’t keep fluids down (vomiting or severe nausea).
- You have moderate to large ketones in your urine or blood.
- Your blood sugar stays above 250 mg/dL despite insulin.
- You feel very weak, confused, or unusually drowsy.
- You develop belly pain, fast or deep breathing, or fruity-smelling breath — these can be signs of DKA.
Call 911 or go to the ER if symptoms are severe or rapidly getting worse.
Helpful resources
Step-by-step guidance for managing diabetes when you’re unwell.
Practical sick-day tips from the ADA.
TeenHealthInsight is a health education website — not a substitute for medical advice. Any questions or worries about your medication, devices, or daily care should be brought to your doctor. Learn here, decide there — always loop in your diabetes team before changing anything you do.