High Morning Blood Sugar Can Ruin Your Sleep—Here’s How to Prevent It (2025)

If you find yourself jolting awake in the early morning hours, it may not necessarily be due to unexplained insomnia. Instead, it could be the dawn phenomenon, a rise in early morning blood sugar levels that can occur in people with diabetes. It typically happens between 2 a.m. and 8 a.m. and is believed to be caused by a combination of factors.

“Our bodies naturally release hormones like cortisol, growth hormone and glucagon in the early morning hours,” explains Maria Teresa Anton, MD, Endocrinologist & Educator at Pritikin Longevity Center. “In people with type 2 diabetes, the body’s ability to regulate blood sugar may be impaired, leading to elevated glucose levels in the morning.”

Unfortunately, this phenomenon that occurs in the early morning hours can actually worsen insulin resistance in those with type 2 diabetes. And women may be especially impacted due to hormonal fluctuations, especially during their period or menopause (these fluctuations can also increase underlying insulin resistance).

How the ‘dawn phenomenon’ affects sleep

There are a few ways that the dawn phenomenon impacts sleep indirectly, according to Dr. Anton:

• It can wake you overnight. Rising blood sugar can cause symptoms like needing to pee often or dry mouth, which may lead to waking up several times throughout the night or struggling to stay asleep.
• It can make you toss and turn. Poorly-controlled blood glucose can trigger lethargy, contributing to restless or fragmented sleep.
• It can rob you of deep sleep. Cortisol, a stress hormone involved in the dawn phenomenon, can interfere with the body’s sleep-wake cycle and reduce your quality of sleep

Those who take diabetes medications like insulin at night to control blood sugar may also experience a “rebound effect” of high blood sugar in the morning hours.

Can high blood sugar in the morning slow weight loss?

It can, largely due to its influence on blood sugar control, insulin levels and metabolism. Because it causes an early morning rise in blood sugar, it can lead to higher insulin levels in people with type 2 diabetes as the body tries to compensate.

“Elevated insulin levels promote fat storage, making it more challenging to lose weight,” says Dr. Anton. “Insulin is a fat-storage hormone, and when insulin levels are consistently high due to blood sugar spikes, it can hinder fat loss efforts.”

When your blood glucose levels fluctuate, it can also result in fatigue or low energy, making it harder to fit in a workout during the day. Plus, the insulin spikes from elevated blood glucose can lead to a subsequent drop in blood sugar, triggering hunger cravings.

4 ways to avoid high blood sugar in the morning

There are a few easy ways you can plan for the dawn phenomenon, and as a result, catch more Zzz’s and keep your metabolism humming, according to Dr. Anton. Here’s what she recommends:

Exercise at night

Evening exercise, even if it’s just a walk around the block post-dinner, can improve insulin sensitivity and lower blood glucose levels.

In fact, moderate to vigorous physical activity in the evening was associated with lower glucose levels during the day and at night compared with being inactive, per a 2024 study in Obesity of adults with overweight or obesity. Although any activity was better than being inactive, evening exercise in particular stood out as being beneficial for blood sugar control.

Have a healthy evening snack

Aim for a blend of protein and healthy fats, like a handful of nuts, at night to ward off high blood sugar levels in the morning. If you’d like to have something sweeter like fruit, opt for a low-sugar choice like berries (which contain more fiber than many other fruits). Eating them with protein like Greek yogurt, cheese or nuts can help balance out the glucose.

On the other hand, high-carb snacks—like that late-night Rocky Road ice cream that calls your name—can cause glucose fluctuations during the night that may trigger the dawn phenomenon in the morning. Avoid sweet treats before bed and you may find you get better sleep as a result.

Establish a bedtime routine

Surprisingly, even good sleep hygiene can help regulate the hormonal fluctuations that contribute to the dawn phenomenon. The American Academy of Sleep Medicine recommends establishing a relaxing bedtime routine, keeping your room at a cool temperature, limiting exposure to bright light and not going to bed unless you’re sleepy.

Consider a glucose monitor

You can also use a continuous glucose monitoring (CGM) device to measure your blood sugar overnight and throughout the day. This will provide real-time blood sugar readings every few minutes, which helps identify patterns in the early morning hours.

“The data from a continuous glucose monitor will show a clear pattern of early-morning blood sugar spikes, allowing you to correlate them with other factors like food, exercise or medication,” says Dr. Anton. “If you do not have access to a continuous glucose monitor, keeping a log of blood glucose trends may be helpful to identify patterns.”

Keep an eye out for symptoms like fatigue, excessive thirst or frequent urination overnight and in the early morning hours, too. “These symptoms might be clues that your blood sugar is rising during the night,” adds Dr. Anton. “If they occur regularly, especially in the early morning, it’s a good indicator that the dawn phenomenon may be impacting you.”

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.