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Patient Resources

Severe Hypoglycemia

February 18, 2022

Glucose, the primary type of sugar in the blood, is the main source of energy for the body and the brain. When blood glucose is low, the body doesn’t have the fuel to function the right way. If blood glucose drops really low, the person is not able to function because physical and mental changes occur. They can have seizures or become unconscious.

Hypoglycemia is the medical term used when the amount of glucose (sugar) in someone’s blood is lower than 70 mg/dL, with symptoms and signs noted above. Hypoglycemia typically resolves when the individual eats or drinks juice, sugar, or other simple carbohydrates.

Hypoglycemia is a very dangerous situation, but a person can take steps to prevent it. If severe hypoglycemia does occur, quick action is needed. If not, it can lead to death. 

KNOW HYPO is a collaborative health campaign, to help improve the “unawareness” or “impaired” awareness of hypoglycemia. Its goal is to help patients and the public recognize symptoms of hypoglycemia early, so action can be taken sooner to prevent complications. It is important for patients, caregivers, providers, and the public to all be in the KNOW.

Endocrine Connection

There are many causes of hypoglycemia, including the treatment of diabetes. Diabetes is a disease in which blood glucose levels are too high. It is often treated with insulin—the hormone that helps move glucose from the bloodstream into your body’s cells—or with medications that increase your body’s insulin production and effectiveness. If these treatments raise your insulin levels too high, your blood glucose can drop too low. Hypoglycemia can also occur if you do not eat when you need to or as much as you need to, or if you skip a meal, drink too much alcohol, or exercise more than usual.

Cortisol, catecholamines and glucagon are hormones that work hand-in-hand with insulin and other hormones in your body to control glucose levels in the blood. Made in the pancreas, glucagon helps to raise blood glucose levels if they are low, and insulin helps to lower blood glucose levels if they are high.

Normally, glucagon begins to act when blood glucose levels are low. It causes the liver to change glycogen (stored glucose) to glucose. This glucose then travels to the bloodstream so the cells can use it for energy. Glucagon also stops the liver from taking in and storing glucose. As a result, more glucose stays in the blood. In addition, glucagon helps the body make glucose from other sources, such as amino acids. This will also add more glucose to the blood.

Hypoglycemia can be mild, moderate, or severe based on the person’s blood glucose and condition. Here are the levels:

  • Level 1 (mild) hypoglycemia: Blood glucose is less than 70 mg/dL but is 54 mg/dL or higher.
  • Level 2 (moderate) hypoglycemia: Blood glucose is less than 54 mg/dL.
  • Level 3 (severe) hypoglycemia: A person is unable to function because of mental or physical changes due to low blood glucose. They need help from another person.

The best way to avoid hypoglycemia is to eat meals and snacks on a regular schedule, test your blood glucose regularly, follow the exercise plan suggested by your diabetes health care team, and always take your diabetes medications as recommended. If needed, eat or drink something before and/or during exercise. Ask your doctor if your diabetes medication can cause hypoglycemia. If it can, ask whether you need to take additional precautions.

Be prepared to check your blood glucose level regularly and especially when you have any symptoms of hypoglycemia. Be prepared to treat those symptoms by keeping glucose tablets or hard candies handy. Make sure family and friends are prepared to help if you show signs of low blood glucose. Also, you should wear a diabetes identification bracelet or necklace to ensure proper emergency care if you are unable to speak for yourself.

You should check your blood glucose level before driving any vehicle or operating machinery to make sure it is in the normal range. This is especially important if you have repeated episodes of hypoglycemia or if you have trouble sensing when your blood glucose is low. Despite how hard you may try, sometimes blood glucose levels may be low even if you have tried everything recommended by your health care team. Remember to take it one day at a time and always try your best.

A mild case of hypoglycemia may cause shakiness, headache, sweating, clammy skin, or a pounding heartbeat. Your blood glucose level falls to 54–69 mg/dL.

If hypoglycemia becomes severe, you may not be able to safely swallow food or drink. By this point, your blood glucose level is less than 54 mg/dL—often below 40 mg/dL. You may feel very confused, pass out, or have a seizure. Without prompt treatment, severe hypoglycemia may lead to a coma or even death.

Often, before a person’s blood glucose drops to a severely low level, they may have some early signs and symptoms. However, some people may not feel any signs or symptoms, so they are unaware that their blood glucose is low. This is a rare condition called “hypoglycemia unawareness” which is most common in patients taking insulin who have chronically low blood glucose levels. If present, some early signs and symptoms of hypoglycemia may be or may include:

  • Sweating or cold, clammy skin
  • Shakiness or dizziness
  • Headache
  • Fast, pounding heart rate

As blood glucose continues to drop, other signs and symptoms may occur, such as:

  • Changes in behavior, such as confusion, irritability, or sleepiness
  • Feelings of being anxious or weak
  • Problems speaking clearly, such as slurring words
  • Problems with vision, such as seeing double or things appearing blurred

As their blood glucose goes even lower, the person may become very confused. Seizures or convulsions may occur. They may lose consciousness and be unable to respond. At this point, they can’t care for themselves and need help. Family, friends, and caregivers will need to act quickly to raise the person’s blood glucose.

Mild hypoglycemia can happen to anyone. For someone who doesn’t have diabetes, severe hypoglycemia is rare, but can also occur as a result of another disease or medicine.

Most cases of severe hypoglycemia occur in people with diabetes who take insulin or certain diabetes medications like sulfonlyureas. Severe hypoglycemia is more common in people with type 1 diabetes since they take multiple injections of insulin daily, but it can also happen in people with type 2 diabetes, especially in those that take insulin. The reason is often due to changes in the balance of the person’s food intake, exercise level, or medicine while taking insulin or other medications for diabetes.

Mild hypoglycemia can be seen in normal individuals when:

  • Fasting
  • Exercising too much
  • Drinking excessive amounts of alcohol

Severe hypoglycemia can occur in people with diabetes who are taking insulin and certain diabetes medications, or changes in overall health. For example:

  • Eating less than the usual amount
  • Skipping a meal
  • Taking too much diabetes medicine
  • Taking diabetes medicine and not eating
  • Exercising too much
  • Drinking alcohol on an empty stomach or drinking too much alcohol
  • Declining kidney function

If hypoglycemia is not corrected right away, it can quickly worsen. You may become very confused and unable to manage your condition. In severe cases, you may even lose consciousness, have a seizure, or go into a coma or die.

Mild to Moderate Hypoglycemia

If you have diabetes and you have symptoms of hypoglycemia, check your blood glucose level right away. If it’s low, you should eat or drink something that will quickly raise your blood sugar. For mild to moderate hypoglycemia, you need to consume 15 grams of carbohydrates, such as 4 glucose tablets, 5 or 6 pieces of hard candy, a cup of milk, 4 ounces of orange juice, or 6 ounces of regular (not diet) soda. Wait 15 minutes and retest your blood glucose level. If it is still low, consume another 15 grams of carbohydrates.

Severe Hypoglycemia

Severe hypoglycemia is an emergency. Treatment focuses on raising the person’s blood glucose quickly with a medicine called glucagon. As a family member, friend, or caregiver, you must step in to help because the person is not able to act on their own. Call 911 or the local emergency immediately is you find someone who is unconscious.

Glucagon helps raise a person’s blood glucose level when it has dropped to dangerous levels. At this point, the person cannot eat or drink anything to help raise their blood glucose. So giving emergency glucagon is the only way to prevent blood glucose levels from dropping even lower. Glucagon kits are available by prescription from a doctor. Glucagon is a medicine that can comes in different forms:

  • Injection kit (glucagon powder and prefilled syringe of saline solution)
  • Auto-injector
  • Nasal Spray

Knowing how to use a glucagon kit can help you act quickly to help raise the person’s blood glucose. The person usually becomes conscious again in about 5 to 15 minutes after you administer glucagon.

Once the person is awake and can swallow, have them eat something that has sugar in it. For example, offer a small piece of fruit, juice, candy, sugar dissolved in water, etc. This will help raise their blood glucose a little higher. Also, have them check their blood glucose after 15 minutes to be sure it is improving.

Call 911 or the local emergency number if:

  • A glucagon kit is not available
  • The person does not respond to the emergency glucagon
  • Blood glucose level is still low even after giving glucagon

As a family member, friend, or caregiver, you want to do your best to keep your loved one, friend, or patient safe from severe hypoglycemia. Knowing what’s best can be overwhelming. Remember severe hypoglycemia is preventable!


Up and Coming Technology

Studies show that repeated episodes of severe hypoglycemia can have a major effect on a person’s ability to manage diabetes and control blood glucose. This condition has also been tied to an increase in heart disease and overall deaths in patients with type 1 and type 2 diabetes. In addition, severe hypoglycemia may have negative effects on a person’s emotional status and quality of life. Scientists are looking for ways to lessen these effects.

Blood glucose monitoring is one area where technology is advancing. Continuous Glucose Monitors (CGMs) are devices that are worn on one’s body that are continuously monitoring your blood glucose 24/7.  It allows patients to know their glucose levels throughout the entire day. 

These devices can also predict if the glucose level might be trending high or low. Some continuous glucose monitoring devices currently available have alarms or alerts to let the person know when glucose levels are too high or too low.The patient can obtain the information through the device’s software or a smartphone app. Other devices can record reports of past levels. This information can be used to predict future levels. All these developments can help the person plan ahead and take action before levels become dangerous.

Hypoglycemia prevention is a critical component of diabetes management. Patients should understand situations that increase their risk of hypoglycemia, such as when fasting for tests or procedures, when meals are delayed, during and after the consumption of alcohol, during and after intense exercise, and during sleep. Hypoglycemia may increase the risk of harm to self or others, such as with driving. Teaching people with diabetes to balance insulin use and carbohydrate intake and exercise are necessary, but these strategies are not always sufficient for prevention.

  • What blood glucose level should alert me to a possible problem?
  • Should I have a glucagon emergency kit? If so, how many do I need?
  • Where should I store the emergency kits?
  • Should I talk with a diabetes educator?

Questions caregivers should ask

As a family member, friend, or caregiver, you want to do your best to keep your loved one, friend, or patient safe from severe hypoglycemia. But knowing what’s best can be overwhelming. Here are some questions to help you get started.

  • What are my loved one’s/friend’s/patient’s chances for severe hypoglycemia?
  • How often should my loved one/friend/patient check their blood glucose?
  • What should I do if there is no change after giving the glucagon?
  • What would be the best food or drink to give my loved one/friend/patient once they wake up?
  • Should I talk with a diabetes educator?
  • How can I help treat their hypoglycemia?

Infographic on understanding glucagon.    Infographic on staying safe from severe hypoglycemia.



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