What is Hypoglycemia Unawareness? Causes, Risks, Prevention

Posted October 5, 2020 by Clint Kelly - See Editorial Guidelines

Have you ever checked your blood sugar and it was low, but you felt normal? This may be a sign of hypoglycemia unawareness, which can be dangerous.

So, in this article, we will explain what hypoglycemia unawareness, why it’s dangerous, and what you can do about it. First, here is a quick answer to get you started.

What is Hypoglycemia Unawareness? This is a condition in which someone is experiencing low blood sugar but does not feel the symptoms. Many factors can increase one’s risk of hypoglycemia unawareness, such as alcohol, exercise, certain medications, and having diabetes for a long time. This can put a person at risk of having serious complications associated with low blood sugar.

With this brief explanation in mind, let’s get into more of the details.

Hypoglycemia Unawareness

What is Hypoglycemia Unawareness

Diabetes patients, especially those that are on insulin, are at an increased risk of having low blood sugar (hypoglycemia). There are many symptoms that come with low blood sugar. Hypoglycemia unawareness is when one does not pick up on the early signs and symptoms of low blood sugar, which may include:

  • Shaky feeling
  • Nervousness or anxiety
  • Sweating
  • Clamminess
  • Irritability
  • Confusion
  • Rapid heartbeat
  • Lightheaded feeling
  • Hunger
  • Nausea
  • Feeling sleepy
  • Feeling weak or fatigued
  • Numbness or tingling of the lips, tongue, or cheeks
  • Headache

Low blood sugar is a level below 70 mg/dL. Typically, patients should start to feel symptoms below this level. It is estimated that roughly 40% of patients with type 1 diabetes suffer from hypoglycemia unawareness, and it is less common in those that have type 2 diabetes.

As someone with diabetes, the first signs that I start to feel include shaking, nausea, and numbness around my mouth. However, there have been moments where my CGM notified me of a low when I was unaware due to not feeling some of the symptoms.

Potential Causes of Hypoglycemia Unawareness

Before covering the potential causes, we have to gain an understanding of what causes the symptoms of low blood sugar to occur. When one’s blood glucose levels drop below 70 mg/dL, the body triggers the release of epinephrine.

Epinephrine, also known as adrenaline, creates what is known as the fight-or-flight response. This can cause the sensation of a pounding heartbeat, sweating, tingling, and anxiety. The brain is also not getting the right amount of glucose it needs to function properly. So, this creates the symptoms of confusion, difficulty concentrating, drowsiness, and slurred speech.

So, with this in mind, here is an outline of the factors that can cause hypoglycemia unawareness.

Have had Diabetes for a Long Time

The longer that a person has had diabetes, the more likely they are to have hypoglycemia unawareness. The longer someone has diabetes, the more likely it is that they have had more episodes of low blood glucose levels compared to those that haven’t had diabetes as long. Evidence suggests that the more episodes one has, the more likely one is to develop impaired hypoglycemia awareness. 


Exercise can cause one’s blood glucose levels to drop both during and after a workout. The feeling of low blood sugar may not be felt or may be confused with the feeling of exhaustion from strenuous exercise.

Low Blood Sugar During Sleep

Many patients experience low blood sugar levels during their sleep. This is partly because one’s cortisol levels are lowest during the night. A person may not wake up and feel symptoms of low blood sugar while they are sleeping. If this occurs often, then hypoglycemia unawareness may become more severe while they are awake.


As people get older, they are more likely to experience some cognitive decline. The decline in cognition can impair one’s ability to notice symptoms of hypoglycemia.

Alcohol Consumption

Alcohol consumption can lead to dangerously low blood sugar levels, as it impairs the liver’s ability to release glucose when the body needs it. Alcohol can make it difficult to pick up on symptoms, and the symptoms may be confused with the tipsy/drunkenness feeling often caused by alcohol.

Prescription Drugs

Certain prescription medications can mask low blood sugar symptoms. So, patients must discuss this risk with their doctor. Prescription drugs that can cause this may include certain beta-blockers and certain selective serotonin reuptake inhibitors (SSRIs).

The Dangers

Hypoglycemia unawareness is dangerous because it can lead to severe and fatal consequences to not just the patient, but those around the patient as well.

Firstly, if your blood sugar is low, and you do not realize it, you will not act immediately to treat it. This can lead to a continuous drop in blood sugar. Dangerously low blood glucose can lead to unconsciousness and seizures. If this occurs, then you cannot treat yourself and must rely on someone else to get you help. However, if no one else is around, then it can lead to death.

In other instances, a person suffering from hypoglycemia unawareness can put others at risk of suffering injury as well. For example, someone with diabetes that has low blood sugar and doesn’t realize it may get in their car and start driving. While they are driving, they could lose consciousness, causing an accident.

What You Can Do About Hypoglycemia Unawareness?

What is Hypoglycemia Unawareness

The best thing you can do about hypoglycemia unawareness is to prevent low blood sugar events from occurring in the first place. You can do this by checking your blood sugar often. This can be done by multiple finger pricks a day or by using a CGM.

Many CGMs provide patients with alerts if their blood sugar drops below a certain level. Checking your blood sugar often allows you to track trends and catch hypoglycemic events before they happen.

Another step you can take is to talk to your doctor about receiving training. Certified diabetes educators can help you navigate the problems you are facing. Your doctor can also adjust your insulin dosages so that your blood sugars are better controlled.

Another step you can take is to look into getting an artificial pancreas, or automated insulin delivery system. This is a system that consists of an insulin pump and a CGM that work together to determine the exact dose of insulin you need. Essentially, this reduces the margin for error. The CGM will sense a drop in blood sugar, signaling the insulin pump to suspend insulin delivery.


Those that have glucagon are always recommended to keep glucagon with them. Talk to your doctor about getting prescribed this medication.

We hope this article has helped you gain a better understanding of hypoglycemia unawareness. As you can see, impaired awareness of low blood sugar can be very dangerous. Discuss specific steps you can take with your doctor.

If you are struggling to afford your medication, then Prescription Hope can help save you money. We work directly with pharmaceutical manufacturers to provide patients with the medicines they need at a set, affordable cost. Enroll with us and start saving money.