Severe Hypoglycemia


Hypoglycemia is the medical term used when the amount of glucose (sugar) in someone’s blood is lower than it should be. Glucose 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 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. 

What is severe hypoglycemia?

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. They need help from another person. In this case, blood glucose is often below 40mg/dL.

What are the signs and symptoms of hypoglycemia?

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:

  • 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

How do you prevent severe hypoglycemia?

For a person with diabetes, the first step in preventing severe hypoglycemia is to keep blood glucose levels under good control. This includes:

  • Eating meals and snacks on a regular schedule after you take your diabetes medications
  • Checking blood glucose levels as directed, especially during the times you are most likely to have a low value (during exercise, when drinking alcohol, when skipping meals, etc.)
  • Sticking to a suggested exercise plan
  • Taking medicines for diabetes on time and as directed
  • Talking to your doctor if you are experiencing frequent episodes of hypoglycemia
  • Carrying juice, candy, or glucose tablets at all times, in the event that one develops symptoms of hypoglycemia 

Another step in preventing severe hypoglycemia is to be prepared. It’s important to recognize the signs and symptoms of hypoglycemia, and once you experience these symptoms check blood glucose levels right away to confirm that you are truly hypoglycemic. If you have a loved one who takes insulin or other diabetes medications, it’s important to check in with the person to make sure that they are checking their blood glucose and following their diabetes plan.

Prevention also means having some type of sugar easily available to treat symptoms if they occur. If blood glucose is low, you can help the person treat the signs and symptoms. Offer them some type of sugar. This can be glucose tablets or gel, fruit juice or regular soda, or some other type of sugar, such as table sugar, honey, corn syrup, or hard candy. Your action can help prevent blood glucose from dropping to severe levels.

How is severe hypoglycemia treated?

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 kits are available by prescription from a doctor. Glucagon is a medicine that is given by injection (auto-injector or intravenously), through oral tablets, or by nasal format. Know how to use a glucagon kit so you can 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

What is glucagon?

Glucagon is a hormone that works hand-in hand with insulin and other hormones in your body to control glucose levels in the blood. Made in the pancreas, glucose 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.

Why do patients need emergency glucagon?

Normally, glucagon works with insulin in the body to keep blood glucose levels stable. Insulin stops glucose levels from getting too high. Glucagon keeps glucose levels from going too low. But with diabetes, this balance gets upset and the hormones don’t function as they should. In persons with diabetes, when blood glucose goes too low, the body is not able to use its own glucagon efficiently to raise blood glucose. That’s why emergency glucagon is given for severe hypoglycemia. It raises blood glucose quickly.

What are the benefits of using emergency glucagon?

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 acts quickly. It causes blood glucose levels to rise within 5 to 15 minutes. The person often becomes conscious again at this time. Glucagon can cause nausea and vomiting. Be alert for these as the person awakens.

Glucagon’s effect on blood glucose lasts only a short time. Be sure the person eats some fast-acting carbohydrate as soon as they are able. This helps to keep blood glucose levels from falling back down.

Who should have glucagon emergency kits?

Glucagon emergency kits are appropriate for anyone who have had previous episodes of severe hyperglycemia, as well as anyone with type 1 diabetes or type 2 diabetes using multiple shots of insulin a day. If the patient is unaware that their blood glucose is low because they do not feel symptoms, an emergency glucagon kit would also be very helpful.

How do I use an emergency glucagon kit?

Most often, an emergency glucagon kit contains a vial of powder (glucagon), a syringe already filled with saline (salt water). Other kits may include an auto-injector, or a nasal spray (see instructions for use of these medications). 

To use a kit by injection, follow these steps:

  1. Check the date on the label to make sure the medicine hasn’t expired.
  2. Remove the vial of powder and syringe from the kit.
  3. Remove the covers from the vial and the needle.
  4. Insert the needle into the vial. Push on the plunger to move the saline into the vial. Remove the syringe from the vial.
  5. Mix the saline and the powder. Gently swirl or roll the vial until the liquid looks clear.
  6. Insert the needle into the vial and draw back all of the liquid into the syringe.
  7. Remove the syringe from the vial.
  8. Inject the needle into the outer part of the person’s thigh, mid-way between the hip and knee or into the arm muscle.
  9. Turn the person onto their side and watch for them to wake up. It may take from 5 to 15 minutes for the glucagon to act.

What’s needed to be prepared for severe hypoglycemia?

Being prepared for severe hypoglycemia is an important part of diabetes management. This involves the person talking with their doctors about the signs and symptoms of low blood glucose and the actions to take. Other areas would likely include keeping blood glucose under control and wearing a diabetes identification bracelet or necklace to ensure proper emergency care for severe hypoglycemia. Using a glucagon kit would also be part of this conversation.

Hypoglycemia Unawareness or Impaired Awareness

The goal is to help a person recognize symptoms of hypoglycemia early on so they can take action sooner. In some cases, if a person does not experience the perceived signs of hypoglycemia this can cause an unawareness. Hypoglycemia unawareness can occur in those patients with diabetes who live with chronically low blood glucose levels. Elderly patients on insulin are at higher risk for hypoglycemia unawareness. The brain and body of those with hypoglycemia unawareness is accustomed to long-standing hypoglycemia, so their normal physiologic response to hypoglycemia is impaired. These people may function and live normally with blood glucose values in the 70's, and only experience symptoms of hypoglycemia when the glucose values drop into the 50's or below. People with hypoglycemia unawareness are at much greater risk of experiencing severe hypoglycemia. It is important to identify those who suffer from hypoglycemia unawareness and find a medication regimen for their diabetes which is safe for them.

As a family member, friend, or caregiver of someone with diabetes, sit down and talk with that person. Find out what their signs and symptoms are and what you should do. Find out at what glucose values do they actually have symptoms of hypoglycemia. If they are not experiencing any signs of hypoglycemia when their glucose levels are in the 60's, this can be life threatening and should be discussed with the doctor right away.  Encourage them to wear some type of diabetes identification. Know where their glucagon kit is for home and work, and when and how to use it.

What new technology is being created to treat severe hypoglycemia?

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. Here are some things they are working on.

Easy-to-use glucagon. New products are being developed. These include giving glucagon as a nasal spray, in a patch through a tiny needle, and in a pre-filled pen. Another idea is the use of micro-doses of glucagon contained in a pen-like device that a person can use when they have mild hypoglycemia.

Improved blood glucose monitoring. Blood glucose monitoring is one area where technology is advancing. Continuous glucose monitors are devices that are worn on one’s body that are continuously monitoring your blood glucose 24/7.  It allows for patients to know their glucose levels throughout the entire day. 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. These devices can also predict if the glucose level might be trending high or 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.

Dual hormone artificial pancreas. Several companies are working to develop an artificial pancreas with two hormones. It would give the person insulin and glucagon to control blood glucose levels. The device would include three elements. A pump would deliver the medicines. A continuous glucose monitoring device would check blood glucose levels. Software would interpret the information from the glucose monitoring device. The software would convert the information into instructions for the pump. The pump would give the person a specific amount of insulin or glucagon based on blood glucose readings.

Questions to ask your healthcare team

  • 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 a 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?
Last Updated:

Find an Endocrinologist

Find an endocrinologist today to ensure that you are on the path to health with the right medical care. Keep Your Body In Balance!

Severe Hypo Survey

We Need Your Feedback!

We are conducting a survey to discover knowledge gaps about severe hypoglycemia for those living with type 2 diabetes. With your help, researchers can develop better resources for diabetes management and prevention. 


About this Content

The Hormone Health Network is the public education affiliate of the Endocrine Society dedicated to helping both patients and doctors find information on the prevention, treatment and cure of hormone-related conditions.

Ensuring the Quality of our Content

All Network materials, including the content on this site, are reviewed by experts in the field of endocrinology to ensure the most balanced, accurate, and relevant information available. The information on this site and Network publications do not replace the advice of a trained healthcare provider.

Advertisements and Site Content

Paid advertisements appear on the Hormone Health Network. Advertising participation does not influence editorial decisions or content.

Back to top