For people with diabetes, the possibility of hypoglycemia, or low blood sugar levels, is always a concern. When a diabetic patient cannot detect a drop in blood sugar levels, a condition known as hypoglycemia unawareness, there is an added layer of complexity.
This is more common and potentially more dangerous than many people think.
This article explains what you need to know about silent hypoglycemia, how to treat it, and steps you can take to prevent hypoglycemia.
What is hypoglycemia?
Hypoglycemia, commonly called hypoglycemia, occurs when the concentration of glucose in the bloodstream falls below normal levels. This is often the result of an imbalance between factors that raise blood sugar levels, such as food intake, and factors that lower blood sugar levels, such as insulin and other hypoglycemic drugs.
Although anyone with diabetes can experience low blood sugar levels, people who use insulin generally experience hypoglycemic symptoms more frequently.
What is considered hypoglycemia varies from person to person based on your medical history, health goals, and the blood sugar levels that you and your health care provider have determined are best for your goal range.
The Centers for Disease Control and Prevention (CDC) describes low blood sugar levels in people with diabetes as less than 70 mg/dL (3.9 mmol/L).
Severe hypoglycemia is considered less than 54 mg/dL (3.0 mmol/L). This requires immediate treatment with fast-acting glucose or glucagon (if chewing or swallowing is not possible).
For more information about hypoglycemia, see below. Symptoms of hypoglycemia (hypoglycemia).
What are the symptoms of hypoglycemia?
Common symptoms of hypoglycemia are:
- trembling
- dizziness
- fatigue/lethargy
- sorrow
- confusion
- sweating
- fast heart rate
- nervous
- hunger
- decreased concentration
- irritation
Symptoms of severe hypoglycemia include:
- slurred speech
- confused thoughts
- loss of consciousness
- seizure
- Top
- Death may occur in rare cases
If you are unable to chew or swallow, or if glucagon cannot be administered or is not effective, call 911 immediately. Severe hypoglycemia can be fatal if left untreated.
Learn more about the symptoms of hypoglycemia below. Symptoms of hypoglycemia (hypoglycemia).
What is unconscious hypoglycemia?
Subconscious hypoglycemia is a condition in which a person does not receive the normal physical warning signs that blood sugar levels are low.
It is much more common than many people realize, and is estimated to affect about 40 percent of people with type 1 diabetes. The disease also affects 10 to 15 percent of people with type 2 diabetes who take insulin or a class of drugs known as sulfonylureas, both of which can cause hypoglycemia.
Taking insulin increases your risk of experiencing low blood sugar levels, and frequent low blood sugar levels can increase your risk of developing unconscious hypoglycemia.
If you are unaware of hypoglycemia, your ability to recognize and respond to early warning signs of hypoglycemia is impaired, thereby significantly increasing the risks associated with hypoglycemic episodes.
Hypoglycemia may become more severe due to lack of consciousness. Without prompt treatment, it can lead to acute complications such as loss of consciousness and seizures, with potentially life-threatening consequences in extreme cases.
Additionally, repeated severe hypoglycemia can lead to long-term complications such as cardiovascular and cognitive problems.
The risk and incidence of experiencing severe hypoglycemia is significantly increased in people who are unaware of their hypoglycemia.
What are the risk factors for unrecognized hypoglycemia?
Some known risk factors for developing asymptomatic hypoglycemia include:
- Long-term use of insulin. Research shows that the longer the duration of insulin treatment, the greater the risk of developing unconscious hypoglycemia. For example, in one study, about half of people who had been using insulin for more than 20 years developed hypoglycemia without realizing it, but only about 20 percent of people who had been using insulin for less than 10 years experienced hypoglycemia.
- History of recent and/or recurrent hypoglycemic events (such as nocturnal hypoglycemia, where hypoglycemia may not be detected or treated).
- Old age.
What causes hypoglycemia without symptoms?
The exact reasons why hypoglycemia goes unnoticed are not fully understood. However, several important factors are believed to have contributed to its development.
- Frequent hypoglycemia can lead to a condition known as hypoglycemia-associated autonomic failure (HAAF), which reduces the sensitivity of the body’s normal alert system to hypoglycemia. Essentially, your body and brain begin to adapt to lower blood sugar levels, and your awareness of hypoglycemic symptoms decreases.
- Tight glycemic control is important for managing diabetes and preventing long-term complications, but paradoxically it can increase the risk of undetected hypoglycemia. This is because aiming for lower blood sugar targets can lead to more frequent episodes of hypoglycemia, thereby increasing the likelihood of HAAF.
Not everyone who takes insulin will experience hypoglycemia without realizing it, but the longer the person has had diabetes, the more likely it is. People who have had diabetes for a long time, especially those who always strive for tight blood sugar control, are at increased risk of developing this condition.
Can drugs cause unconscious hypoglycemia?
Certain drugs, such as beta-blockers, mask symptoms of hypoglycemia, such as heart palpitations and tremors, making it harder to detect an impending hypoglycemia. This is because it blocks the action of adrenaline.
These drugs treat conditions such as angina (a type of chest pain), heart failure, and high blood pressure, but their effects on adrenaline can make early signs of hypoglycemia more difficult to detect.
Selective serotonin reuptake inhibitors (SSRIs), used to treat depression, may also mask mild symptoms, although their effects are unclear.
Additionally, alcohol can interfere with blood sugar regulation and mask symptoms of low blood sugar levels. And this substance can be doubly problematic, as it can also increase your chances of losing strength.
Are there complications from not recognizing hypoglycemia?
If you are not aware of hypoglycemia, your risk for both short-term and long-term complications increases significantly.
Without the typical early warning signs of hypoglycemia, the situation is more likely to become serious by the time it is recognized and treatment is attempted. Such severe low blood pressure can impair important functions, making it difficult to perform daily activities such as driving, reading, and working, and can impair judgment and cognition.
If hypoglycemia is not treated quickly enough, it can even lead to more serious complications such as loss of consciousness, seizures, coma, and brain damage. Over time, repeated episodes of severe hypoglycemia can also lead to cardiovascular complications and cognitive decline.
How can I prevent and treat silent hypoglycemia?
If symptoms of hypoglycemia are no longer detectable, contact your health care provider.
Most people with diabetes can feel hypoglycemia when their blood sugar levels reach 70 mg/dL (3.9 mmol/L), but this level may be different for people who have a history of frequently low blood sugar levels.
If a diabetic is unaware of hypoglycemia, formal programs exist to improve blood sugar awareness. Additionally, your health care provider can discuss ways to become more sensitive to low blood sugar levels.
Your health care provider may suggest reducing your daily insulin dose, slightly increasing your target blood sugar range, or changing your physical activity routine to prevent low blood sugar levels in the first place.
You may also be able to catch hypoglycemia sooner by checking your blood sugar more often or wearing a continuous glucose monitor (CGM). It’s also a good idea to carry fast-acting carbohydrates to quickly treat hypoglycemia, and to have a glucagon kit on hand in case of severe hypoglycemia (glucagon is a hormone that helps raise blood sugar levels).
For some people, a diabetic alert dog (DAD) may provide additional security by alerting them to hypoglycemia. However, this option requires consideration of the associated training and commitment.
Additionally, some people have found that switching to slow-acting insulin can help if they have persistent, silent hypoglycemia. These insulins have a slower release time and a more predictable blood sugar lowering effect, which may help prevent severe blood sugar drops.
For those who have access to this technology, the use of automated insulin dosing (AID) systems can greatly help prevent hypoglycemia.
These systems use the values from the CGM and run them through an algorithm to determine how much insulin to deliver through the pump. When blood sugar levels drop, insulin is reduced or paused, which helps prevent hypoglycemia.
Several AID systems are available in the United States, including the Medtronic MiniMed 770G system, the Medtronic MiniMed 780G system, the Tandem Diabetes Care t:slim X2 with Control-IQ technology, and the Omnipod 5 automated insulin dosing system.
Hypoglycemia unawareness cannot always be reversed, but susceptibility can be increased, primarily by avoiding low blood sugar levels for a while.
Work closely with your doctor to tailor these approaches to your specific needs and circumstances.
Tips to prevent hypoglycemia
Although hypoglycemia cannot be prevented in all cases, you can minimize its frequency by using the following strategies:
- See your doctor or endocrinologist regularly to adjust your medication.
- To more accurately count carbohydrates, consider using a food scale.
- Eat meals and snacks on a schedule.
- To reduce the risk of exercise-induced hypoglycemia, avoid exercise if your blood sugar level is less than 100 mg/dL (5.6 mmol/L) or if you have recently taken insulin.
- To reduce the risk of nocturnal hypoglycemia, avoid going to bed with blood sugar levels below 100 mg/dL (5.6 mmol/L).
- Take all insulin and other medications as prescribed.
- If you consume a certain amount of carbohydrates, make sure you eat all the carbohydrates you consume.
- Drink alcohol, if at all, in moderation.
- Avoid drinking alcohol if your blood sugar level is less than 100 mg/dL (5.6 mmol/L).
- Always carry fast-acting glucose with you to treat ailments.
- Consider wearing a CGM.
- Set CGM low and predictive low alerts to “on”.
- Treat hypoglycemia early before it becomes dangerous.
final thoughts
Managing hypoglycemia unawareness requires a variety of strategies. Regular monitoring of blood glucose levels, especially using CGM devices, plays an important role in the early detection and management of hypoglycemic symptoms.
Consulting with your health care professional to adjust your insulin dosage and treatment plan can also help reduce the risk of undetected hypoglycemia.
Lifestyle modifications such as meal planning, careful monitoring of physical activity, and responsible alcohol consumption are also important to manage blood sugar levels and avoid hypoglycemia. In some cases, the support of a diabetic alert dog can provide additional safety even when hypoglycemia cannot be detected.
If you’re not aware of your low blood sugar levels, it’s important to talk to your health care provider to discuss strategies tailored to your specific needs. With the right combination of medical feedback, self-care, and support tools, it is possible to effectively manage this condition and reduce the risk of serious complications.
