High Blood Sugar at Night: What It Means and What to Do by Mehdi Yacoubi

High Blood Sugar at Night: What It Means and What to Do
Posted on
July 8, 2021

Your body is a complex machine working around the clock to maintain a healthy status quo. Muscles flex, tendons stretch, nerves fire, and over 10 different organ systems communicate to support one another throughout the day. 

At some point, however, your body decides it needs to rest after all that endless work. As you get ready for bed and drift off to sleep, these systems remain active and alert. And one of them — the circulatory system — regulates your blood glucose levels.

From body weight to sleep habits, many factors influence your blood glucose (sugar) levels when you sleep. But if these levels are irregular at night, what should you do to regain control? And how can you stabilize them again, whether they're high or low? Here are some tips and strategies to help you understand and manage your blood glucose levels before bed and through the night.

What Happens to Your Blood Sugar at Night?

In order to understand how your blood sugar changes, first, we need to discuss the hormone known as insulin. Produced by the cells of your pancreas, this incredibly important molecule plays a pivotal role by helping your cells absorb sugar from carbohydrates within your blood. From there, the sugar is turned into usable energy that provides power to your entire body.

As important as insulin is, it doesn't always work the way it's supposed to. For instance, we experience blood sugar spikes in the middle of the night during a process known as the dawn phenomenon. In non-diabetics, insulin handles this nighttime surge by absorbing excess glucose from the blood to keep blood sugar levels stable. But for those who have diabetes (or might have diabetes), insulin can't do its job, and blood sugar levels rise.

Years of research have allowed us to identify normal, low, and high blood sugar levels. According to the World Health Organization, healthy fasting levels fall between 70 mg/dL and 100 mg/dL. When levels are between 100 and 125 mg/dL, healthcare professionals are more likely to diagnose prediabetes because levels are higher than normal. And any reading higher than 126 mg/dL is diagnosed as diabetes. Though we often associate the use of a continuous glucose monitor, or CGM, with diabetes, anyone can use this simple instrument as a preventative measure to gain a better understanding of their overall health.

Symptoms of irregular blood glucose levels vary but may include dizziness, headaches, anxiety, sweating, fatigue, and even hunger. If you've experienced these symptoms, consider speaking with a healthcare provider to determine if you're diabetic or in need of medical intervention.

What Affects Your Blood Sugar Levels at Night?

There are many risk factors that influence your blood sugar levels at night. Let's take a closer look at a few of them below.


Diabetes comes in two forms, or types: Type 1 and Type 2. Type 1 diabetes occurs when your body can't produce insulin because it attacks and destroys the cells in your pancreas that produce insulin. Those that suffer from Type 1 diabetes will monitor their insulin levels and employ an insulin pump that delivers doses of insulin as needed.

Type 2 diabetes, on the other hand, occurs when your body doesn't make or use insulin as it should. Sometimes your body doesn't make enough insulin, suffers from decreased insulin sensitivity, or builds up an insulin resistance. Either way, this form of diabetes requires a regular insulin dose, often via injection, before meals to help your body process carbs. It's also the most common type of diabetes — about 90-95% of people diagnosed with diabetes have Type 2.


Individuals designated as obese can develop a natural resistance to insulin over time if the underlying obesity is left untreated. That's because obesity causes inflammation and increased levels of fatty acids that counter insulin. This can lead to prediabetes, as well as Type 2 diabetes if some form of diabetes management isn't established. 

​Eating Habits

Though everyone's body responds differently to food, unhealthy eating habits can cause your blood sugar to spike during the night. That said, you'll recall that the dawn phenomenon also causes your blood sugar levels to rise naturally. For this reason, it's important to determine why your blood sugar is rising and if it is doing so because of your eating habits. For those with diabetes, consider eating a bedtime snack that's high in fiber and healthy fats, as these will keep your blood sugar steady and prevent your liver from releasing excess glucose.

Sleep Habits

Believe it or not, your sleep habits can affect how your body responds to insulin over time. Sleep disorders such as sleep apnea can also raise a person's odds of having diabetes, as a lack of sleep is a natural risk factor for increased blood sugar.

Managing Your Blood Sugar Levels at Night

High blood sugar at night: A bowl of nuts and dried fruit

Once you've understood why your blood glucose levels rise at night, the next step is to establish a plan that manages these levels. Use the following strategies to help regulate your blood sugar levels at night.

Drink Water

Your body will attempt to rid itself of excess sugar in various ways, but one common way is through urination. To facilitate this process at night, consider drinking enough fluids during the day and before bed. Avoid sweetened beverages like soda and stick with water whenever possible.


You've been told time and time again that exercise contributes to your overall well-being, but it also helps you manage your blood sugar levels by burning blood glucose as fuel. For those following an insulin treatment plan, exercise may require you to inject insulin less often because your insulin sensitivity will increase and improve how your body uses glucose.

Monitor Your Eating Habits

What you eat will directly influence your blood sugar levels. A large dinner, late-night snack, and poor diet can negatively impact how your body manages its blood sugar. If you're craving a snack, consider taking a blood sugar reading to help you determine if you have high or low blood sugar. Based on this information, you can choose foods that will balance or regulate your blood sugar. For instance, those suffering from low blood sugar, or hypoglycemia, would benefit from eating fresh or dried fruits. Those experiencing hyperglycemia, or high blood pressure, would benefit from eating a personalized diet that reflects readings from your CGM. This becomes especially important for those suffering from diabetes.

Practice Good Sleep Hygiene

Sleep hygiene refers to the routines you follow before bed and the environment in which you sleep. To practice good sleep hygiene means you're maintaining a normal sleep schedule, removing distractions from your bedtime routine such as electronics, and building habits during the day that contribute to restful sleep at night. Now that we know sleep directly influences blood sugar levels, it's important to establish habits that contribute to quality sleep each and every night.

Monitor Your Blood Sugar Levels

Consider monitoring your blood sugar levels if you're prediabetic, diabetic, or looking to understand the connection between your body and things like diet, exercise, and energy levels. Doing so will help you develop strategies to manage your blood sugar levels and provide you with a plan of action when your levels are irregular.

Work with a Healthcare Team

Talk to your doctor or a licensed healthcare professional before implementing any strategies that seek to manage your blood sugar levels. The patient-doctor partnership is a pivotal relationship in medicine that allows you to receive high-quality care whether you're experiencing sudden insulin resistance or unforeseen complications as a result of diabetes.

Lowering Your High Blood Sugar at Night

High blood sugar at night: A woman checks her CGM readings on her cellphone

As we've learned, blood sugar levels are subject to change throughout the day as a result of habits and conditions. From the quality of your sleep to your body weight, the variables at play can quickly become overwhelming, but there are steps you can take to monitor and manage your blood sugar. 

Consider investing in a personalized health system like Vital's continuous glucose monitor and app to gain a better understanding of what's happening within your body. Even if you’re healthy, active, and attentive, you can still benefit from this information that takes the guesswork out of how your body is performing. Then, based on the data, you can receive personalized and actionable recommendations to optimize your metabolism. Doing so will allow you to manage your blood sugar and maintain healthy levels each and every night.

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