Middle of the Night Madness: A Guide to Overnight Blood Sugar Swings
If you’re the parent of a child with Type 1 Diabetes, you probably know the feeling all too well- waking up in the early hours, heart pounding, wondering:
Are they too high?
Are they too low?
Have I actually been to sleep yet?
Welcome to Middle of the Night Madness, where T1D parents survive on instinct, adrenaline and endless cups of coffee. Overnight blood sugar swings can feel unpredictable- one night it’s steady, the next you’re battling a hypo at 3 AM. Don’t worry, you’re not alone! With a few simple strategies, you can reduce those restless nights and help your child wake up in range.
Who Do Overnight Highs & Lows Happen?
Blood sugar doesn’t stay still just because your child is asleep. A few key factors can throw things off:
The Dawn Phenomenon- In the early hours (typically between 3-6 AM), the body releases hormones that naturally raise blood sugar, often leading to unexplained morning highs.
Too Much Insulin Before Bed- A slightly overestimated correction dose at bedtime can cause a drop later in the night.
Delayed Exercise Effects- A day of running around or sports can cause blood sugar to drop hours later, often during sleep.
Slow-Digesting Foods at Dinner- Meals high in fat and carbs (like pizza, pasta, or a takeaway) can lead to delayed spikes long after your child has gone to bed.
How to Keep Blood Sugar Stable Overnight
Now that we know why nighttime swings happen, here’s how to reduce the chances of highs and lows before they start.
1. The Bedtime Blood Sugar “Safe Zone”
Ideally, your child should go to sleep with a steady blood sugar between 5.5-10 mmol/L (This might differ for your child so always check with your child’s diabetes team for their advice).
Too high? A gentle correction may help, but avoid overdoing it.
Too low? A small, balanced snack can help prevent a night-time hypo.
Avoid the “rage bolus” trap! It’s tempting to give extra insulin for a stubborn high at bedtime, but overcorrecting can cause a crash later in the night.
2. Pick the Right Bedtime Snack (If Needed!)
If your child is prone to night-time hypos, a small snack can help keep blood sugar steady. The best options include:
Peanut Butter on Wholemeal Toast- A good mix of slow-release carbs and protein.
Greek Yoghurt with Berries- High in protein with natural sweetness.
Cheese & Wholegrain Crackers- Balanced fat, protein and carbs to stabilise blood sugar.
Avoid: Sugary snacks like biscuits, sweets or fruit juice before bed, as these can cause a quick spike followed by a crash.
3. Set a Night-Time Alarm (But Not Every Night!)
If your child is newly diagnosed, had an active day or you’ve changed insulin settings, a 2-3 AM check can be helpful.
If you notice frequent overnight highs or lows, consider adjusting their long-acting insulin, dinner dose or bedtime snack (always discuss with your diabetes team who will be able to guide any changes).
Pro Tip: If your child uses a CGM- set alerts for low and high readings so you only wake up when necessary.
4. Adjust for Active Days
Gentle exercise (like walking) may not have the huge impact overnight.
High-intensity activities (like football, swimming or dance) can lower blood sugar hours later, even in the early hours.
What Helps?
A slightly lower evening insulin dose (only if advised by your diabetes team-always check with them before making any changes to insulin).
A bedtime snack with protein & slow-digesting carbs.
Checking levels before bed to see if extra precautions are needed.
5. Catching the Dawn Phenomenon
If your child’s blood sugar rises between 3-6 AM, they might be experiencing the Dawn Phenomenon- a natural surge of hormones that causes high morning readings.
Solutions:
If using an insulin pump, try adjusting basal rates during early morning hours.
If on injections, speak to your diabetes team about potential adjustments to long-acting insulin.
How to Get More Sleep as a T1D Parent
Let’s be honest- managing diabetes at night is exhausting. Here are a few ways to ease the burden:
Rotate Night Checks- If possible, share the responsibility with a partner or other family members.
Use CGM Alerts- If your child wears a CGM like a Dexcom or Libre, set low and high alarms so you only wake up when necessary.
Track Patterns- Keeping notes on night-time readings can help you spot trends and adjust insulin doses with your diabetes team.
Give Yourself Grace- Some nights will be unpredictable, and that’s okay. If you’re exhausted, try to nap when you can and reach out for support if needed.
Final Thoughts
Night-time blood sugar swings can feel like an endless battle, but with a few tweaks to bedtime routines, insulin doses and snacks, you can reduce the number of wake-ups and help your child start the day in range.
