You know what it’s like after a night of poor sleep. You wake up tired and sluggish, reaching for coffee to get through the day.
But what you might not realize is that missing sleep doesn’t just drain your energy. Poor sleep can also alter how your body handles blood sugar (glucose). And if you have diabetes, it could make managing blood sugar even more difficult.
“Sleep and blood sugar are closely linked,” said Sarah Tariq, MD, an endocrinologist with Banner - University Medicine. “When you don’t get enough sleep, your body enters a stress mode that can raise blood sugar. And if your blood sugar is out of balance, it can disrupt your sleep even more.”
This back-and-forth cycle can be hard to break. Learn more about how sleep and blood sugar influence each other, the most common sleep issues faced by people with diabetes and what you can do to protect your health.
How sleep – or lack of it – impacts blood sugar and insulin
When you don’t get enough sleep, your body reacts as if it’s under stress. The stress hormone, cortisol, increases. High cortisol levels cause your liver to release more glucose into your bloodstream.
Over time, this can cause insulin resistance, a condition where your cells don’t respond to insulin properly. At the same time, hyperglycemia (high blood sugar) or hypoglycemia (low blood sugar) can disrupt sleep.
“High blood sugar can cause symptoms like frequent urination, thirst and nighttime trips to the bathroom,” Dr. Tariq said. “On the other hand, low blood sugar during the night triggers an adrenaline response. You may wake up sweating, with a rapid heartbeat or feelings of anxiety, which affects your rest.”
How stress and sleep affect blood sugar
Stress and sleep often influence each other. Cortisol signals your body to release glucose for energy. This response was useful for survival in the past but it can cause problems today, especially when stress is chronic.
“Elevated cortisol contributes to insulin resistance, weight gain and higher blood sugar levels,” Tariq said. “Chronic stress can also increase the risk of developing type 2 diabetes two to three times. Short or disrupted sleep can raise your risk by 40% to 80%.”
The combo of stress and poor sleep affects more than blood sugar. It can cause cravings for sugary or high-carb foods, mood swings and difficulty concentrating. This influences overall health and quality of life.
Common sleep problems in people with diabetes
If you live with diabetes, you may already know how much sleep can be disrupted by blood sugar changes. According to the American Diabetes Association, common sleep disorders include:
- Obstructive sleep apnea (OSA): Breathing repeatedly stops and starts during sleep. This is seen in both type 1 and type 2 diabetes.
- Insomnia: Difficulty falling or staying asleep.
- Restless leg syndrome (RLS): Uncomfortable sensations in the legs that make it difficult to relax and fall asleep.
- Circadian rhythm disorders: Disruptions in your natural sleep-wake cycle.
“These conditions contribute to fragmented (restless) sleep, hypoxia (low oxygen levels) and increased insulin resistance,” Dr. Tariq said. “Over time, this can worsen blood sugar control and raise the risk of cardiovascular disease.”
Even tools meant to help, like continuous glucose monitors (CGMs) and alarms, can disrupt sleep if overused.
“The best strategy is to use the data from CGMs wisely to prevent nighttime highs and lows, rather than letting alarms dominate your night,” Dr. Tariq said.
Adjusting bedtime snacks, checking medication timing with your provider and keeping supplies nearby can reduce disruptions without compromising safety.
Signs your sleep may be affecting your blood sugar
Connecting fatigue or poor sleep to blood sugar can be challenging, but some signs are:
- Waking up with higher morning blood sugar than usual
- Feeling unusually tired or irritable during the day
- Frequent nighttime trips to the bathroom
- Snoring, gasping or restless nights
- Morning headaches, dry mouth or difficulty concentrating
If these signs feel familiar, improving your sleep may help.
Steps to improve sleep and support blood sugar
“A lot of us get caught up in our day-to-day and do not realize some of the things we may be doing that are leading to poor sleep quality,” Dr. Tariq said. “Small changes in your routine can have a big impact.”
Some steps you can take include:
- Limit caffeine: Try not to have any caffeine after 12 p.m.
- Avoid late-night meals: Try to finish eating at least four hours before bed.
- Stick to a regular sleep schedule: Go to bed and wake up at the same time every day even on weekends.
- Create a bedtime routine: Wind down with reading, gentle stretches or deep breathing to signal your body it’s time for rest.
- Optimize your bedroom: Keep it cool, dark and quiet. Blackout curtains or white noise machines can help.
- Reduce screentime: Blue light from phones and other screens can interfere with circadian rhythm. Stop using devices at least two hours before bed, if possible. If screens are needed, try blue-light glasses.
- Move during the day: Exercise improves insulin sensitivity and helps you fall asleep faster. Avoid intense workouts just before bed.
- Manage stress: Journal, meditate or do yoga.
When to seek professional help
Chronic sleep problems shouldn’t be ignored. Talk to your health care provider if you:
- Sleep less than six hours most nights
- Struggle to fall or stay asleep
- Feel excessively tired despite adequate sleep
- Have high blood sugar despite following your care plan
Your provider may recommend a sleep study, a specialist or adjustments to your diabetes management plan. Addressing these sleep issues can improve blood sugar control, energy and overall well-being.
Takeaway
Getting quality sleep is one of the most important things you can do for your health, especially for your blood sugar. When you don’t sleep well or are stressed, your body can have a harder time using insulin and you can increase your risk for diabetes and other health problems.
[Are you at risk for diabetes? Take this short questionnaire.]
By building better sleep habits, managing stress effectively and using your diabetes tools wisely, you can protect your health and feel more energized.
Make sleep a priority. If you have questions or concerns, talk to your health care provider or a Banner Health specialist.
Schedule an appointment with a sleep medicine specialist.
Schedule an appointment with an endocrinologist.
