Hypoglycemia unawareness: when you don’t know you’re going low
The content in this article should not be taken as medical advice. Please consult your healthcare provider regarding your individual health needs and Dexcom alert settings.
Hypoglycemia unawareness, also known as hypo unawareness, is when you don’t experience or recognize the symptoms of low blood sugar. Hypo unawareness is a common complication of diabetes. Around 25 percent of individuals living with type 1 diabetes (T1D) experience it and around 10 to 15 percent of those living with type 2 diabetes (T2D) experience it as well.1
It’s important to understand what hypo unawareness is, how it happens, and what to do if you develop it because it plays an important role in diabetes management and your overall health and well-being.
What is Hypoglycemia?
Hypoglycemia is low blood sugar. Our bodies use sugar, also known as glucose, from the foods and drinks we consume for fuel. Hypoglycemia happens when there isn’t enough glucose in the blood to be used for energy. It’s more likely to occur in individuals who manage their blood sugar with insulin.3 This is because insulin helps the cells in the body absorb glucose. When there’s more insulin and not enough glucose coming into the body, it runs out of fuel too quickly.2
The American Diabetes Association (ADA) defines glucose levels below 70 mg/dl as hypoglycemia.4 Dropping below 50 mg/dl is considered severe hypoglycemia4 and requires urgent medical attention. In general, the ADA recommends that individuals living with diabetes keep their glucose between 70 mg/dl and 180 mg/dl.4
Everyone’s experience of hypoglycemia is different. Those experiencing hypo unawareness may no longer experience symptoms at all and certain medications can even mask or hide symptoms. A handful of the initial low blood sugar symptoms that individuals may experience include5:
- Shaking or sweating
- Having a headache or feeling lightheaded, weak, or drowsy
- Having a fast heartbeat
- Being irritable, nervous, or anxious
- Having difficulty concentrating
Symptoms of worsening hypoglycemia can look like5:
- Loss of coordination, slurred speech, or confusion
- Blurry vision or tunnel vision
- Having nightmares (during a nighttime hypo)
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Understanding hypo unawareness
Hypo unawareness is not a personal failing or a lack of judgment. It’s something that happens to the brain and nervous system as the body experiences hypoglycemic events. Individuals who have lived with diabetes or used insulin for a long time are more likely to experience challenges around feeling hypoglycemia in their bodies.1 Researchers are still working to determine why hypo unawareness happens and ways to reverse it.
If you’re experiencing hypo unawareness, know that it’s not your fault.
What are the most common causes of hypoglycemia unawareness?
Hypo unawareness happens as the body gets used to experiencing frequent or severe hypoglycemic events over time. When your glucose levels go low, the body sends signals in the form of symptoms—such as shaking, sweating, or feeling irritable—to alert you that something is wrong, and you should take action. However, when individuals repeatedly experience hypoglycemia, the body builds up a tolerance and doesn’t send out these signals right away. In addition, there are certain drugs, including beta blockers for hypertension, that can hide symptoms of hypoglycemia. As time goes on, the body might stop sending signals entirely, which means that you won’t be able to feel when you’re experiencing a severe low.1,6
Nocturnal hypoglycemia, or experiencing hypos while you sleep, can increase the risk of developing hypo unawareness.7 When you’re asleep, your body is not as responsive to hypoglycemia, so you’re more likely to sleep through a low.7 The more often an individual experiences nighttime hypos, the less sensitive their body will be to them, which further contributes to hypo unawareness.7 Alcohol also reduces the body’s sensitivity to hypoglycemia, which can lead to more frequent hypos and, in turn, increased hypo unawareness.7
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Can you prevent or reverse hypo unawareness?
Glucose management is key to reducing the risk of developing hypo unawareness and improving sensitivity to symptoms. Avoiding hypoglycemia for several weeks can help the body re-learn how to react to low blood glucose levels.6 It’s important to talk to your doctor and diabetes care team if you’re having challenges with hypoglycemia and hypo unawareness. They can help you create a personalized diabetes care plan to help you control your glucose levels and avoid hypos as often as possible.
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Preventing hypoglycemia
You can work on preventing hypoglycemia by managing your glucose levels. There are many factors that can affect your glucose beyond just food and exercise. You and your doctor will work together to come up with a diabetes management plan that will help you spend more time in your target glucose range and avoid hypoglycemia. If you’re using insulin therapy, it’s a good idea to understand how different types of insulin work. Be sure to talk to your doctor and diabetes care team about your insulin so that you can create dosing routines that work best for you.
It’s also important to talk to your doctor about how to treat hypoglycemia when it happens. Treating a hypo in the moment typically requires you to consume glucose to boost your levels back up to a healthy range. When experiencing hypoglycemia,
the ADA recommends that individuals get 15 grams of simple carbohydrates, such as juice, regular soda, or hard candy and
check their glucose again after 15 minutes, then repeat until their glucose is at least 70 mg/dL. Once your blood glucose is back to normal, eat a meal or snack so it doesn’t lower again.6
Understanding hypo unawareness
Experiencing hypo unawareness can be stressful and even scary. Continuous glucose monitoring (CGM) systems like Dexcom G7 can help you be proactive about preventing hypoglycemia even if you’re experiencing hypo unawareness. The Dexcom G7 sensor takes glucose readings under your skin by measuring the glucose in the interstitial fluid that surrounds your cells and continuously sends the readings to a display device, such as a compatible smart device or receiver.* This can provide a real-time view into where your glucose has been, and where it’s going, so you can worry a little less about knowing when you’re low.
Using Dexcom G7 is clinically proven to help individuals living with diabetes reduce hypoglycemia, spend more time in their target glucose range, and lower A1C.8-13 Dexcom CGM Systems are also proven to help those living with T1D who experience hypo unawareness reduce the frequency of hypos.13
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Dexcom G7 has several critical features that can help
keep you in the know about low glucose—even before
it happens.
Urgent Low Alert
Dexcom G7 has a built-in Urgent Low Alert that can notify you the moment your glucose drops below 55 mg/dl. The Urgent Low Alert is a mandatory safety feature of Dexcom G7 and is always on, this can give you greater confidence that you’ll be able to catch a low when it happens, even if you can’t feel it.
Smart device sold separately.*
Remote monitoring with Dexcom Follow
With the Dexcom Follow app, friends, parents, and caregivers can keep an eye on a loved one's glucose levels remotely by receive glucose alerts on their compatible smart device.† This adds yet another layer of support can empower them to better support children and individuals dealing with hypo unawareness by providing greater visibility into what’s going on with their glucose, even if they aren’t in the same room.
Using the Dexcom Follow† app has been shown to help individuals living with T1D decrease the frequency of hypoglycemia and feel more confident about managing hypos. It has also been shown to help those living with T1D get a better night’s sleep, reduce diabetes-related stress, and increase their overall sense of well-being.15
Smart device sold separately.*
Get started on Dexcom G7
If you live with diabetes and do not use CGM, talk to your doctor about Dexcom G7. We can help you get started with a free benefits check. Click the button below to send us some basic information.
For a list of compatible smart devices visit http://www.dexcom.com/compatibility
† Separate Follow app and internet connection required. Users should always confirm readings on the Dexcom CGM System app or receiver before making treatment decisions.
1 Seaquist, E. How hypoglycemia unawareness affects people with diabetes - NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. Published April 5, 2023. https://www.niddk.nih.gov/health-information/professionals/diabetes-discoveries-practice/how-hypoglycemia-unawareness-affects
2 Hantzidiamantis PJ, et. al. Physiology, Glucose. StatPearls Publishing. Updated September 19, 2022. Accessed July 18th, 2024. https://www.ncbi.nlm.nih.gov/books/NBK545201/
3 Lega IC, et al. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Hypoglycemia in Adults. Can J Diabetes. 2023;47(7):548-559. doi:10.1016/j.jcjd.2023.08.003
4 American Diabetes Association Professional Practice Committee; 6. Glycemic Targets: Standards of Medical Care in Diabetes—2022. Diabetes Care 1 January 2022; 45 (Supplement_1): S83–S96. https://doi.org/10.2337/dc22-S006
5 Mayo Foundation for Medical Education and Research. Hypoglycemia -Symptoms and Causes. Mayo Clinic. Published November 18, 2023. https://www.mayoclinic.org/diseases-conditions/hypoglycemia/symptoms-causes/syc-20373685
6 Understanding and managing low blood glucose (hypoglycemia). Hypoglycemia-Signs, Symptoms, & Treatment. American Diabetes Association. Accessed August 1, 2024. https://diabetes.org/living-with-diabetes/treatment-care/hypoglycemia#
7 Harnish, A. A guide to navigating nighttime hypoglycemia. The diaTribe Foundation. Published March 25, 2024. https://diatribe.org/diabetes-management/guide-navigating-nighttime-hypoglycemia
8 Beck RW, et al. JAMA. 2017;317(4):371-378.
9 Beck RW, et al. Ann Intern Med. 2017;167(6):365-374.
10 Martens T, et al. JAMA. 2021;325(22):2262-2272.
11 Laffel LM, et al. JAMA. 2020;323(23):2388-2396.
12 Welsh JB, et al. J Diabetes Sci Technol. 2024;18(1):143-7.
13 Heinemann L, et al. Lancet. 2018;391(10128):1367-1377. doi:10.1016/S0140-6736(18)30297-6
14 Puhr S, et al. Diabetes Technol Ther. 2019;21(4):155-158. doi:10.1089/dia.2018.0359
15 Polonsky WH, et al. Diabetes Technol Ther. 2021;23(3):195-202. doi:10.1089/dia.2020.0466
2 Hantzidiamantis PJ, et. al. Physiology, Glucose. StatPearls Publishing. Updated September 19, 2022. Accessed July 18th, 2024. https://www.ncbi.nlm.nih.gov/books/NBK545201/
3 Lega IC, et al. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Hypoglycemia in Adults. Can J Diabetes. 2023;47(7):548-559. doi:10.1016/j.jcjd.2023.08.003
4 American Diabetes Association Professional Practice Committee; 6. Glycemic Targets: Standards of Medical Care in Diabetes—2022. Diabetes Care 1 January 2022; 45 (Supplement_1): S83–S96. https://doi.org/10.2337/dc22-S006
5 Mayo Foundation for Medical Education and Research. Hypoglycemia -Symptoms and Causes. Mayo Clinic. Published November 18, 2023. https://www.mayoclinic.org/diseases-conditions/hypoglycemia/symptoms-causes/syc-20373685
6 Understanding and managing low blood glucose (hypoglycemia). Hypoglycemia-Signs, Symptoms, & Treatment. American Diabetes Association. Accessed August 1, 2024. https://diabetes.org/living-with-diabetes/treatment-care/hypoglycemia#
7 Harnish, A. A guide to navigating nighttime hypoglycemia. The diaTribe Foundation. Published March 25, 2024. https://diatribe.org/diabetes-management/guide-navigating-nighttime-hypoglycemia
8 Beck RW, et al. JAMA. 2017;317(4):371-378.
9 Beck RW, et al. Ann Intern Med. 2017;167(6):365-374.
10 Martens T, et al. JAMA. 2021;325(22):2262-2272.
11 Laffel LM, et al. JAMA. 2020;323(23):2388-2396.
12 Welsh JB, et al. J Diabetes Sci Technol. 2024;18(1):143-7.
13 Heinemann L, et al. Lancet. 2018;391(10128):1367-1377. doi:10.1016/S0140-6736(18)30297-6
14 Puhr S, et al. Diabetes Technol Ther. 2019;21(4):155-158. doi:10.1089/dia.2018.0359
15 Polonsky WH, et al. Diabetes Technol Ther. 2021;23(3):195-202. doi:10.1089/dia.2020.0466
BRIEF SAFETY STATEMENT: Failure to use the Dexcom Continuous Glucose Monitoring System and its components according to the instructions for use provided with your device and available at https://www.dexcom.com/safety-information and to properly consider all indications, contraindications, warnings, precautions, and cautions in those instructions for use may result in you missing a severe hypoglycemia (low blood glucose) or hyperglycemia (high blood glucose) occurrence and/or making a treatment decision that may result in injury. If your glucose alerts and readings from the Dexcom CGM do not match symptoms, use a blood glucose meter to make diabetes treatment decisions. Seek medical advice and attention when appropriate, including for any medical emergency.