It’s 2 AM when Maria’s low glucose alarm wakes her partner. Maria is awake, but something isn’t right. She knows she needs the glucose tab on her nightstand, but she’s too shaky. When trying to ask for help, her speech is garbled. Her partner steps in, hands her the tabs, but she is too foggy to open the package herself. Thankfully, he opens the tabs and helps her take them.
Within a few minutes, Maria feels like herself again. She never lost consciousness. No one called 911. So, when her care team asks at her next appointment whether she’s had any severe hypoglycemic events lately, she says no.
If this sounds familiar, you're not alone, and you may be underestimating what you've actually been through.
As a researcher focused on bettering the lives of people living with diabetes, including treatment of severe hypoglycemia, I hear versions of Maria's story frequently. And I want to clear something up: what happened to Maria absolutely counts as severe hypoglycemia. Understanding why can change how you talk to your care team and allow you to work together to reduce the risk of future events.
Most people think of low blood glucose, or hypoglycemia, on a simple scale: a low, and then a "bad" low.
A severe hypoglycemic event is one where your glucose has dropped low enough that you experience altered mental or physical function, meaning you need help from someone else to treat and recover.
The American Diabetes Association defines hypoglycemic events in 3 levels.
What’s important about this definition is the things it does not include. No specific number. No hospital visit. No need to only consider events where glucagon is used. Just: Could you treat it yourself, or did you need another person to step in?
About 1 in 5 adults with T1D report having at least one severe hypoglycemic event in the past year, even while using a CGM or an automated insulin delivery (AID) system.
Source: T1D Exchange Registry follow-up survey
Severe hypoglycemia doesn’t always look the way people expect. A few common myths can make these events surprisingly easy to overlook.
Myth: It has to end in unconsciousness or a seizure to "count."
Reality: Most severe hypoglycemic events never get anywhere close to that point. More often, they look like Maria's: too shaky or foggy to manage a simple task, speech that's slower or harder to understand than usual, unsteady on your feet, making it difficult to walk to where rapid-acting carbs are located, or feeling too disoriented to safely treat yourself. If you needed someone else's help, even something as small as opening a tab wrapper for you, that event meets the clinical definition of severe.
Myth: It's all about the number on your CGM.
Reality: Glucose matters. After all, this is diabetes. But it's not what defines a severe event. What matters is whether your body and brain were physically and mentally able to treat the low on your own. Two people can have the same glucose reading, yet only one may be unable to function well enough to self-treat. That's the person having a severe event.
Myth: If it happens to you, it means you're not managing your diabetes like you “should.”
Reality: This one matters the most to me. Let me say it plainly: a severe hypoglycemic event is not a personal failure, nor a report card on how well you're managing your T1D. It can happen even with the latest diabetes technology and everything you can do to manage your glucose. It can happen to anyone with T1D. Bottom line: managing diabetes is hard.
If you’re a parent or caregiver, severe hypoglycemia can be especially difficult to recognize in children. You’re naturally going to step in and help treat a low. The key distinction is whether your child could have treated the low on their own. Were they confused or disoriented? Could they drink the juice or take the glucose tabs on their own? If they couldn’t safely treat themselves because of a low, that’s when the event may be considered severe.
What Is Impaired Awareness of Hypoglycemia?
Many of us are taught to expect warning signs before glucose drops too low, like shakiness, sweating, a racing heart, or sudden hunger. Those symptoms are your body's early alarm system.
For some people with T1D, that alarm system quiets over time or goes silent. This is called impaired awareness of hypoglycemia (IAH). If you have IAH, you have little to no warning when a low occurs. This effectively condenses the time you have to safely treat yourself, making it much harder to treat a low before it becomes severe. The symptoms you get with lows are like your car’s blind-spot warning. With IAH, you have no idea what is coming; a crash could be in the not-too-distant future.
IAH is more common than you might think, and it isn't something you did wrong. If you have repeated lows, you can be at greater risk of developing IAH. Your body adjusts and may stop warning you in the same way. It can occur at any time while living with diabetes, months, years, or even decades into your diagnosis. It tends to go hand in hand with a higher risk of severe events.
Over 30% of adults with T1D are classified as having impaired awareness of hypoglycemia, according to T1D Exchange Registry data, regardless of the diabetes technology they use.
Source: T1D Exchange Outcomes Research Spotlight
The good news is that IAH isn't a mystery your care team has to guess at. There are simple questions you can use to help you and your care team talk about it.
For example, I might ask: “If your glucose is 70 mg/dL, do you feel low?” Yes. No. Sometimes.
This isn't a pass-or-fail test. It's the starting point for a conversation. If your answers suggest your awareness has changed, your care team can talk with you about adjusting your glucose targets, alarm settings, or treatment plan to help reduce your risk of future lows. Notably, if you avoid having lows for a period of time, your body’s ability to warn you often returns.
Understanding the real definition of a severe hypoglycemic event changes what you choose to share with your care team, and that matters for getting the care and support you need.
If you're not sure whether something you experienced counts as severe, my advice is simple: tell your care team about it anyway. I would always rather hear about an event that turns out not to meet the clinical definition than have someone stay quiet about one that does. When in doubt, over-report. Let your care team help you sort out what it means.
Two more things I want every person with T1D and every caregiver to know, because they don't come up nearly often enough:
1
Ask your care team about a prescription for glucagon, and keep it current and accessible. Glucagon is the emergency treatment for a severe low. Having it on hand and making sure the people around you know how to use it can make a real difference. Since 2019, ready-to-use glucagon therapies have been available. No more complex kit that requires multiple steps, you can get either nasal glucagon or a pen similar in construct to an EpiPen.
2
In the 24 hours after a severe hypoglycemic event, you're at increased risk of having another one. Your body has been through something significant, and it needs time to recover. This is often a good time to be more cautious with insulin dosing and to check in with your care team about your glucose trends, rather than assuming things are back to normal right away.
For years, I would have told you that severe hypoglycemia didn’t happen to me.
Then, while working on a research study on nasal glucagon treatment, I sat down to help write the paper's clinical definition of severe hypoglycemia. And as I wrote it out, I realized it had actually happened to me.
I had a newborn at the time. I was walking through my house holding him when I suddenly felt very weak. I sat down on the kitchen floor and laid him down gently on the tiles beside me. My teenage daughter walked in and found me struggling to get words out. We keep a red jar of glucose treatment in our kitchen, and she knew exactly where it was (no kids allowed, this is just for mom!). She brought me some candy, I treated, and within a few minutes, I felt like myself again.
In my head, I still told myself I hadn't had a severe hypo event. I hadn't passed out. I hadn't had a seizure. I didn’t get glucagon. And nobody asked me about it afterward, so I never had a reason to call it what it actually was.
There was something else going on, too, something I think may resonate with others. As a person living with T1D myself, I didn't want to acknowledge that this could happen to me. I was judging myself, like it meant I wasn't managing my TID well, even though I know better. I was doing everything right.
This disease is what's difficult. I am not the problem.
That is exactly why I believe so strongly in asking, every single time, and encourage everyone to be honest about what's happening at home. If I could miss my own severe hypoglycemic event while I was actively researching this exact topic, I understand how others may have drawn the same conclusion, “that low wasn’t so bad”.
My daughter has carried some fear from that moment, and I don't take that lightly. It's part of why I make sure I always have glucagon readily available (in my purse, in a kitchen cupboard, on my desk), and why I talk about this so openly now, with my patients and with my own family. It turns out you can be a pediatric endocrinologist living with type 1 diabetes and still have severe hypoglycemic events. If it can happen to me, with everything I know about this disease, it can happen to anyone with T1D. None of us should feel ashamed of that.
Later in this series, we’ll go beyond the event itself to explore the ripple effects severe hypoglycemia can have on daily life, relationships, and long-term well-being for people living with T1D and their caregivers.
Medical Disclaimer: T1D Exchange does not provide medical advice. The information in this article is for educational and informational purposes only and is not intended to replace guidance from your healthcare provider. If you have questions or concerns about your health, treatment, or diabetes management, please talk with your healthcare provider.