7 Reasons for high morning blood sugars

Published on: 07/24/2022
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Why are my blood sugars high in the morning when I didn’t even eat anything before bed the night before?

This is one of the most common questions I get, and understandably so. Logic would tell us that if we are not eating for several hours during the night our blood sugar will go down, not up – right? 

Unfortunately our body is way more complicated than that. So why do blood sugars sometimes go up overnight?

I will give you some common reasons and explanations that will hopefully help you better understand what’s happening.

Here are 7 possible reasons why you might be getting higher fasting blood sugars.

Insulin resistance

This is the underlying problem with type 2 diabetes and the most common reason for morning highs, especially if you are early in diabetes and not on medication. Insulin resistance simply means that your body is making enough insulin but is not able to use it effectively to keep blood sugars in normal range.  What causes it? The most common reasons are not being active and extra body fat. 


Hormones that work opposite insulin are released to wake us up, and some have a stronger effect than others. Did you know insulin is actually a hormone? So when cortisol and other hormones increase our body needs to get more insulin working to compensate and keep blood sugars from rising. But when we have insulin resistance it doesn’t work as well.   


If you have chronic pain due to other health conditions, that also creates more resistance to your body’s insulin working properly.

Not Sleeping well

Every night blood sugars increase during sleep due to circadian rhythm but normally our pancreas releases the right amount of insulin counteract that increase and keep blood sugar level healthy in normal range. Night shift workers or those that don’t sleep well tend to have more trouble with blood sugars due to lack of sleep or good quality sleep. 

Late night meals or snacks

It could be food related but only if you are eating large amounts late at night. If you stay up late and binge eat too much carb food, it is possible that blood sugar is going high and staying high enough that it is still high when you wake up.  


There are so many meds and some can have a side effect of increasing blood sugar but I am going to talk just about common diabetes medication effects.

Occasionally I see high morning blood sugars because of night lows. If you are on insulin or pills such as glipizide or glimepiride, those can cause low blood sugar if the dose is too high or you have not eaten for a long time. It’s not uncommon to discover lows at night that you don’t know are happening.

If I am working with a client and I suspect that might be happening, I will recommend a continuous glucose monitor (wearing a sensor) for 2 weeks to make sure blood sugar is not dropping too low. You would be surprised at how many people are having lows at night and don’t know it!

When blood sugar drops too low our liver releases sugar to try and get it back up to a safe level, but sometimes it goes too high. Or maybe you did feel low and ate or drank more sugar than you needed and then your blood sugar spikes up high.  If you are on insulin or those medications I mentioned above and you suspect you could be having lows, talk to your doctor or diabetes educator. This can be a dangerous situation!

For example if your blood sugar is low and you get up to use the bathroom at night, you could get dizzy and fall. Restlessness or having night sweats could be signs of blood sugar dropping too low. 


Chronic high stress can keep blood sugars higher as well. I have seen this happen in situations where people have a very stressful job and when they go on vacation their blood sugars are much better. Stress, pain and sleep can be difficult factors to change.

If you are having morning high blood sugars and struggling to get your A1c to target, I would recommend working with a CDCES (Certified Diabetes Care & Education Specialist). We have the time, tools and training to look at many factors and help you figure out the solution. 

Contact me or click here to find a CDCES in your area


Meet the Author
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Thanks for visiting my blog!

I’m Karen, a diabetes nutrition specialist who is passionate about fighting diabetes for my clients, my family, and myself.

I hope you find food ideas and answers to some of your questions here in my articles. But if you are looking for more personalized help with nutrition or diabetes please check out my services page.

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