How Sleep and Stress Affect Blood Sugar | University Health

By Angela Williams

August 08, 2025

You were diagnosed with prediabetes at your last checkup. You know your blood sugar is too high, but what causes that? The answer might surprise you.

When many people think about high blood sugar or diabetes, they think about eating too much sugar. While excessive consumption of added sugars can certainly increase your blood sugar and your risk of developing diabetes, it isn’t the only factor.

Many different factors, including your lifestyle habits, play a role in maintaining a healthy blood sugar level — or on the flipside, of developing high blood sugar.

Here’s what you should know about two potential causes of higher-than-normal blood sugar, also called blood glucose: not getting enough sleep and having high stress levels.

The Connection Between Sleep and Blood Sugar

Sleep plays a major role in helping you maintain good health and wellness. As you sleep, you get vital rest and recuperation, benefiting all the systems and organs in your body.

That includes the endocrine system, which is responsible for producing insulin that helps your body manage blood sugar. Getting enough sleep can help you maintain a healthy blood sugar level.

Why Blood Sugar Rises During Sleep

Oddly enough, as you sleep, your blood sugar actually increases. While you might think that’s a bad thing for your health, it’s actually just part of your body’s natural processes.

The human circadian rhythm causes the release of certain hormones to prepare the body to wake up in the morning, including cortisol and epinephrine. Those hormones trigger the liver to release glucose, which causes a temporary increase in blood sugar.

This is called the “dawn phenomenon,” since it typically causes increased blood sugar between 4 a.m. and 8 a.m., the dawn hours. For most people, this temporary fluctuation isn’t even something you’d notice, but if you have diabetes, a medical provider may suggest adjusting your medications to help the body handle the sleep-related blood sugar increase.

How Much Sleep Is Enough Sleep?

The Sleep Foundation and other health experts recommend that most adults get between seven and nine hours of sleep each night. Older adults may get by with only seven or eight hours.

If you find yourself struggling to get enough quality sleep on a regular basis, take a close look at your habits. Make your bedroom a haven for sleep — it should be cool, dim and quiet. Removing electronics from the room may help you fall asleep more easily and stay asleep.

It can also be helpful to create a bedtime routine. While we often think of such routines as something for children, having a routine also benefits adults because it helps the body know when it’s time to wind down to sleep. Stick with a consistent bedtime and wake time to keep your body in a good sleep rhythm.

Looking for help navigating a diabetes diagnosis? Ask your primary care provider to refer to University Health Texas Diabetes Institute.

Stressing Out Your Blood Sugar

Above, we talked about how the release of certain hormones causes your blood sugar to increase as you sleep. Those hormones, specifically, are stress hormones.

Stress hormones are released when the body thinks it’s in danger. These are a holdover from when you might have encountered a mammoth or a saber-toothed tiger while out walking. They’re designed to put the body into “fight or flight” mode, so you can escape from danger or fight against it.

It’s still possible to encounter danger that requires making an escape or escalating a fight, but these days, stress hormones are often triggered by entirely different types of stress, such as situations in your relationships or at work.

Just like when those stress hormones are released as part of the sleep cycle, they elevate your blood sugar any other time they’re released. That means that stress can also increase your blood sugar.

How Stress Affects the Body

Even when you aren’t facing off with a saber-toothed tiger, stress can make your body react as if you were. When your eyes spot a danger, even if that danger is an irritating coworker, they send a distress signal to the brain.

The brain then communicates with the rest of the body through the nervous system. When that happens:

Your body releases stress hormones
You experience a burst of energy
Your heart beats faster than normal
Your pulse and blood pressure increases
You may breathe more rapidly
Your senses sharpen

One other thing that happens? Extra blood sugar is released into the bloodstream to help provide that burst of energy you might need when fleeing or fighting.

What You Can Do to Manage Stress

A small amount of stress is entirely normal, but when you face too much stress or chronic stress, it can wreak havoc on your body. If you’re stressed most of the time, your blood sugar stays elevated most of the time, too.

In some cases, that can lead to the development of Type 2 diabetes, and if you already have diabetes, it can make the condition more difficult to manage.

While there’s no way to totally eliminate stress from life, you can take steps to help your body and mind manage the effects of stress. Take these steps to help your body better handle stress and keep your blood sugar in a healthier range:

Exercise regularly. Moving your body when you can, as much as you can, can help you maintain good overall health and reduce stress. Aim for around 30 minutes of physical activity each day.

Find a relaxation routine. Meditation, yoga, mindfulness, deep breathing or prayer can help your body reset and remain calm.

Lean into your support system. Talk with your friends and family members about stressful situations. They may be able to help you solve the problem or they may at least be able to lighten things up.

Write it out. Keeping a journal can also give you an outlet for stressful feelings and situations. Or you could keep a gratitude journal noting what you’re thankful for, which can refocus your mind.

Comprehensive Diabetes Care at University Health

Take control of your diabetes before other health complications arise. Ask your primary care provider for a referral to our Texas Diabetes Institute.

At the Texas Diabetes Institute, we offer comprehensive services to prevent and treat diabetes under one roof. You will find expert and compassionate endocrinologists, along with other specialists, ready to help you.