Diabetes Sick Day Guidelines

What to eat, how often to monitor glucose, and when to check for ketones during illness

Getting sick can throw your entire routine off—especially if you’re managing blood sugar. Whether it’s a cold, flu, or stomach bug, your body responds with stress hormones that can raise glucose levels even if you’re eating less than usual. Having a clear plan helps you stay safe and recover more smoothly.

🥣 What to Eat When You’re Sick

When you're ill, your appetite may drop—but your body still needs fuel.

If you can eat normally:

• Stick with balanced meals (carbs + protein + healthy fats)

• Choose easy-to-digest foods like oatmeal, rice, toast, eggs, soups

If you can’t eat solid foods:

• Try liquids with carbohydrates:

  • Broth-based soups

  • Fruit juice (small amounts)

  • Sports drinks (if needed for carbs + electrolytes)

  • Smoothies

General rule: Aim for ~15 grams of carbohydrates every hour or so if you’re not eating full meals.

Stay hydrated:

• Sip fluids every 15–30 minutes

• Alternate water with electrolyte drinks if needed

📊 How Often to Monitor Glucose

Illness can cause unpredictable glucose swings, so frequent monitoring is key.

Recommended frequency:

• Check every 2–4 hours (even overnight if levels are unstable)

• If using a CGM, keep a closer eye on trends and alerts

Watch for:

• Persistent highs (above your target range)

• Rapid rises or drops

• Signs of dehydration (which can affect readings)

🧪 When to Check for Ketones

Ketones can build up when your body doesn’t have enough insulin—this is especially important for people with diabetes.

Check ketones when:

• Blood glucose is over 240 mg/dL

• You have fever, vomiting, or diarrhea

• You feel symptoms like:

  • Nausea

  • Abdominal pain

  • Fruity breath

  • Rapid breathing

How often:

• Every 4–6 hours while glucose is elevated or symptoms persist

Seek medical help if:

• Ketones are moderate to high

• You can’t keep fluids down

• Blood sugar stays high despite insulin

⚠️ When to Call Your Healthcare Provider

Don’t wait it out if things feel off. Reach out if you have:

• Persistent blood glucose above 250 mg/dL

• Moderate or large ketones

• Vomiting or diarrhea lasting more than 6 hours

• Signs of dehydration (dry mouth, dizziness, low urine)

✔️ Quick Sick Day Checklist

• Stay hydrated

• Eat small amounts regularly

• Monitor glucose every 2–4 hours

• Check ketones if glucose is high or symptoms appear

• Continue taking insulin (never stop without guidance)