What is Nocturnal Hypoglycemia?

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Having a diabetic grandson who sometimes spends the night with us we found it important to understand what is nocturnal hypoglycemia and learn what to do should it occur.

The first thing to understand is that nocturnal (night time)hypoglycemia is something that can happen to anyone who has diabetes.

It occurs more frequently in type 1 diabetics or anyone who is taking insulin.

Nocturnal hypoglycemia simply means low blood sugar at night while sleeping.

This can be dangerous because the person may not wake up to know their sugars are low and treat them.

Untreated lows can cause unconsciousness and death.

Let`s take a closer look.


Some people wake up when they experience nocturnal hypoglycemia.

However, if this is not the case for you, you may still notice one or more of the following indicators that hypoglycemia may have occurred while you were asleep and you should discuss these symptoms with your doctor.

  • restless, irritable sleep
  • hot, clammy or sweaty skin
  • trembling or shaking
  • changes in breathing (too fast or too slow)
  • nightmares (sometimes rousing the person from sleep)
  • racing heartbeat

Doctors are even more concerned when people do not wake and continue to sleep through these symptoms.

Our grandson, Alex, is hypoglycemia unaware so he does not awaken when his sugars go too low at night.

What is Nocturnal Hypoglycemia - wearing a CGM can helpThankfully he wears a CGM so nighttime checks are easily done. Just a quick scan and we know what his sugars are doing.

Naturally, if he scans low, we always do a finger poke to get a current reading and then treat the low accordingly.

For Alex, a few sips of apple juice does the trick and by using a straw to drink he doesn’t even have to fully wake to drink.

When he was first diagnosed we were testing him every hour throughout the night because his levels would drop that suddenly.

Since they have changed his insulin and also the timing of his long-lasting insulin he doesn’t drop so suddenly but he does go low at night sometimes.

Now we check him every 2 or 3 hours throughout the night so we can catch the lows before they are dangerous.

What causes nocturnal hypoglycemia

Several things can increase the chances of experiencing a nocturnal(night time) hypos including:

  • a high basal (background) insulin level
  • increased physical activity which can affect blood sugar levels for several hours afterwards
  • alcohol consumption
  • skipping a bedtime snack when you usually have one
  • skipping dinner
  • following a period of illness
  • if basal insulin has been increased

With Alex, we rarely know why he goes low at night. When we had him on the boat over the summer we believed the extra activity from swimming may have contributed.

We all work diligently to follow his diabetes care plan as closely as possible and treat lows as soon as they are noticed.


Treating Nocturnal (night time) hypoglycemia is the same as treating any low.

Simply take 10 to 15 g of a fast-acting sugary food (such as sweets, glucose tablets or fruit juice) and testing blood sugars again in 15 minutes to ensure the levels are rising.

Also taking a slower acting carb such as a slice of bread can help prevent a further hypo from occurring.

To make nighttime treatments easier it is a good idea to keep some fast-acting sugary snacks by the bed.

What is Nocturnal Hypoglycemia - fast-acting sugar snacks or fruit juice treat lowsA glass of fruit juice or some glucose tablets or skittles is a perfect choice.

Alex has become so accustomed to being checked throughout the night that it doesn’t even fizz on him.

Seriously though, we go in and scan him, if he is in a position that the disk isn’t accessible we just say “Time to scan you, Bud”. He will roll over so the disk is easy to read.

If he is low and we need to do a finger poke, we simply tell him we need to poke his finger, he will then stick out his hand in our direction.

He can even take a few sips of apple juice if he is low.

He does all this without even opening his eyes which I find so amazing.

If it were me, I would be fully awake and unable to go back to sleep.

Just goes to show how truly resilient kids really are.


What is Nocturnal Hypoglycemia- test glucose levels oftenAs with most diabetic complications, prevention is always preferred.

Always follow your diabetes care plan as directed by your diabetes care team.

Ensure you have your meals on time and take all medications as prescribed.

Don’t exercise in the evening.

Have an evening or bedtime snack containing carbohydrates.

Be sure to check your blood glucose levels before bedtime.

For those who take 2 or more insulin shots each day, it is a good idea to aim for keeping your blood glucose above 6.5 mmo/l before bed.

If you suspect you have been having nocturnal hypos it is a good idea to set your alarm for 2 or 3 am to test blood sugar levels.

When combined with the before bed and the first thing in the morning test this will help you determine what your blood sugar levels are doing overnight.

If you discover your blood sugar levels are dropping too low overnight you may need to adjust your insulin levels.

Never adjust your insulin without consulting your diabetes care team.

As I have mentioned in previous posts, life with diabetes does take a few adjustments but once you figure it out it isn’t so bad.

Everything just becomes second nature.

We have a little black bag or for hiking the backpack that always goes wherever Alex goes.

We have what we need to test his sugars or treat lows at all times. We also have water and insulin with us to help control highs as well.

Final Thoughts

What is Nocturnal Hypoglycemia is a topic every diabetic or their caregivers need to understand.

If you suspect you or someone you care for is experiencing nighttime lows be sure to talk with your diabetes care team.

Symptoms can include:

  • restless, irritable sleep
  • hot, clammy or sweaty skin
  • trembling or shaking
  • changes in breathing (too fast or too slow)
  • nightmares (sometimes rousing the person from sleep)
  • racing heartbeat

We have learned that you treat nocturnal (night time) hypoglycemia, in the same manner, you would treat any hypo.

Eat a fast-acting sugar and retest blood glucose in 15 minutes to ensure it is rising closer to the target range.

Often, nighttime low blood sugars can be prevented by diligently following your diabetes care plan as set forth by your diabetes care team.

I am not in any way a medical practitioner, please do not rely on the information on our website as an alternative to medical advice from your doctor or another healthcare provider. We only share our experiences.

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2 thoughts on “What is Nocturnal Hypoglycemia?”

  1. Hey,

    This is such an important and informative article. I’m sorry to hear about your grandson, but I must say, he looks really cool in his photograph. I can tell he is going to grow up to be someone special. I’ve definitely heard of Nocturnal Hypoglycemia, but I didn’t know how you can notice it or it’s symptoms. Thankfully, I am not seeing anything of the symptoms, but I do have family members who are diabetic. so, I am going to share this article with them, just incase they are seeing these symptoms but don’t know what it is.

    Thank you for sharing and keep up the great work.

    Oh, and keep raising your grandson t be super cool 🙂

    All the best,


    • Thanks for sharing this article with your family, Tom. I definitely appreciate it. I am thankful you haven’t noticed symptoms in your family members. I am sure your family members are grateful you were already aware of nocturnal hypoglycemia because you would be able to lend assistance if it were necessary. Education is so critical in helping keep our family members safe and healthy and this is even more important with diseases such as diabetes. I am glad I was able to give you the knowledge of what symptoms to watch out for. Oh and thanks for the comment about Alex, we think he is a pretty cool kid with a great sense of humour.


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