A Guide to Navigating Nighttime Hypoglycemia
Key takeaways:
- Nighttime hypoglycemia, sometimes called nocturnal hypoglycemia, is when blood glucose levels drop below 70 mg/dL during the night.
- Symptoms include sweating, restlessness, confusion, disrupted sleep, headache, anxiety, and potentially loss of consciousness.
- Nighttime hypoglycemia can be scary, but there are ways to minimize the risk, including using a continuous glucose monitor (CGM) alone or as part of an automated insulin delivery (AID) system and making lifestyle changes like reduced alcohol use.
Picture this: You’ve had one of those glorious and productive days. You delivered a major work project, acquired two weeks of groceries, and still got an evening walk in.
But during the night, you wake up unexpectedly, and something’s not right. You’re drenched in sweat. Maybe you’re a little shaken up because of nightmares, or even scarier, you’re confused.
You check your blood sugar and it’s dangerously low. What’s going on? You’ve experienced nighttime hypoglycemia.
Acting fast after an episode of nocturnal hypoglycemia is critical. Here’s what to know about this common condition, including what to do and how family or other caregivers can play a role.
What is nighttime hypoglycemia?
Also known as nocturnal hypoglycemia, this condition occurs when blood glucose levels drop to very low levels (below 70 mg/dL) during the night. As the body relies on glucose for energy, low blood sugar levels can lead to disruptions in normal bodily functions during sleep, causing a range of symptoms.
Nocturnal hypoglycemia is a common challenge for people living with diabetes, especially those using insulin.
“Hypoglycemia is more concerning at night because the individual may not recognize symptoms while sleeping, leading to prolonged and potentially severe hypoglycemia,” said Dr. Reza Nazemi, an endocrinologist at Cedars Sinai in Los Angeles.
What causes nighttime hypoglycemia?
The causes of hypoglycemia during the night vary widely, but a common cause is excess insulin.
“Too much insulin can be taken before bed to correct high sugars and cover meals or snacks, but then insufficient food is eaten before bedtime,” said Dr. Betul Hatipoglu, medical director of the Diabetes and Obesity Center at University Hospitals Cleveland Medical Center.
“It can also be the effect of exercise done in the evening, which can continuously impact the nighttime blood sugars,” Hatipoglu said.
Drinking alcohol (especially without food) can play a role, Nazemi added. Other illnesses, such as viruses, kidney disease, thyroid disease, and liver disease, can contribute to nighttime lows. Medications like beta-blockers can also increase the risk.
Symptoms of nighttime hypoglycemia
Warning signs can be subtle and each person experiences them differently, but here are the main symptoms to watch out for:
- Night sweats: Experiencing excessive sweating during sleep is a classic sign of nighttime hypoglycemia. The body responds to low blood sugar by releasing stress hormones, triggering sweating as a mechanism to raise blood sugar levels.
- Disrupted sleep: You may experience restlessness, anxiety, nightmares, or difficulty staying asleep due to the physiological stress caused by low blood glucose.
- Waking with a headache: A morning headache can be an indicator of nighttime hypoglycemia, as the brain is sensitive to fluctuations in blood sugar levels.
- Cognitive symptoms: Low blood sugar can affect cognitive function, leading to irritability, confusion, or difficulty concentrating.
- Seizures or loss of consciousness: These can occur in severe cases.
While nighttime hypoglycemia can happen to anyone managing diabetes, some may be at higher risk than others. Risk factors for nighttime lows include experiencing low blood sugar frequently during the daytime (or not feeling it during the day), older age, dementia, and kidney disease.
What to do if you experience nighttime hypoglycemia
Treating hypoglycemia at night is similar to what you would do during the day.
“If you wake up feeling symptomatic, immediately check your blood sugar,” Nazemi said.
If it's low (typically below 70 mg/dL), consume a fast-acting carbohydrate like glucose tablets, fruit juice, or regular (non-diet) soda, then recheck your blood sugar after 15 minutes.
“Repeat if necessary, and follow up with a snack containing protein and carbohydrates,” Nazemi said.
Friends, family, and other caregivers also have an important role to play. If severe nocturnal hypoglycemia occurs, you may be too disoriented to act or unable to eat or drink. In that case, a ready-to-use glucagon pen or nasal formulation should be used.
Make sure the people around you know the signs so they can help out in an emergency. If an emergency kit is unavailable, calling 911 may be the best option.
How to prevent nighttime hypoglycemia
Low blood sugar is concerning any time of day, but when it happens at night, you often can’t act immediately as you would when awake.
That’s why it’s important to take steps to prevent nocturnal hypoglycemia. The same tactics that prevent daytime hypoglycemia – regularly monitoring blood sugar and recognizing the signs – are the first steps.
“Analyzing and trying to find the cause is essential to prevent future episodes,” Hatipoglu said. “If possible, asking for a continuous glucose monitoring device for the future can be helpful.”
Nighttime hypoglycemia can be frustrating and scary, but there are steps you can take to mitigate the effects. Staying vigilant and educating yourself and others around you can go a long way toward keeping you safe from this all-too-common phenomenon. Lifestyle changes like reducing alcohol intake and keeping up with diabetes management can help avoid or reduce nocturnal hypoglycemia.
Using a continuous glucose monitor (CGM) can help. The device sends audio and vibration alerts that your blood sugar is dropping so you can correct it before it’s too low.
For people using insulin, automated insulin delivery (AID) systems have also been shown to help with nighttime lows. A recent study found that AID systems, specifically the MiniMed 780G, helped correct nighttime lows and highs, leading to fewer sleep interruptions from CGM alerts.
If you’re experiencing symptoms of nighttime hypoglycemia, speak to a healthcare provider who can recommend a CGM, AID system, or other course of treatment.
Learn more about managing highs and lows here: