11 Things You Need to Know About Low Blood Sugar (Hypoglycemia)

Low blood sugar, or hypoglycemia, is a potentially dangerous condition that’s most common in people with diabetes using certain medications to control a body’s blood sugars. Hypoglycemiaoccurs when blood sugar levelsfall lower than normal and can lead tolife-threating complications. If you or a loved one has recently been diagnosed with diabetes, make sure to talk with your care team about how to maintain your health in the face of this potentially fatal disease. Below, we've listed everything you need to know about hypoglycemia.

11 Things to Know About Hypoglycemia

1. What is low blood sugar, also known as hypoglycemia?

Your body’s blood sugar levels measure the amount of glucose present in your blood stream. Glucose is the building block of the carbohydrates you eat and is your body’s primary source of energy. Hypoglycemia is a condition in which your blood sugar (glucose) level is lower than normal. Blood sugar treatment goals can vary from person to person, but in general for people with diabetes, blood sugar levels should be 70 to 130 mg/dL before meals (preferably around 100), and less than 180 mg/dL after meals. For people with diabetes, a blood sugar of less than 70 can be considered hypoglycemia and action may need to be taken to prevent continued decrease of this blood sugar level. Speak with your care team about your personal blood sugar targets.

2. What causes hypoglycemia?

Hypoglycemia can occur due to a variety of factors. Most commonly it can occur from some of the medications used to manage diabetes. Although, less common, hypoglycemia can also be caused by other medications, drinking excessive alcohol, critical illnesses, hormone deficiencies, and insulin overproduction. It can even happen as a result of irregular eating habits such as skipping a meal while using certain medications to manage diabetes. It’s important to speak with your care team to determine which factors are putting you at risk for hypoglycemia and how you can prevent it.

3. How common is hypoglycemia?

Hypoglycemia, causes approximately 100,000 emergency room visits per year in the U.S. Many people think hypoglycemia is something that only occurs in people with diabetes, however it can affect anyone who’s blood sugar levels fall lower than normal. For most individuals, treatment involves quickly getting your blood sugar back up with high-sugar foods, drinks, or medications. Talk with your care team if you’re always thirsty, urinating more often, have gained or lost significant amounts of weight, or have any other health concerns.

4. What are the risk factors for hypoglycemia if you have diabetes?

Diabetes is a condition in which the body either does not produce enough insulin or if your cells are not able to use insulin effectively. Diabetes medications work by helping to regulate insulin levels, however some of these drugs also may increase the risk of developing hypoglycemia.

Other risk factors include:

  • Consuming an excessive amount of alcohol
  • Age - Speak with your clinician to find out how this may affect you
  • Having irregular eating habits, such as skipping a meal or eating less than usual (if using glucose lowering medications such as sulfonylurea or insulin)
  • Increasing your physical activity without enough nutrition
  • Using excessive amount of insulin

If you have diabetes, talk with your care team about the medications you are taking and how to treat a hypoglycemic episode before it becomes severe. Hypoglycemia has different presentations from excessive sweating or rapid heart rate, to seizures, loss of consciousness and, in severe cases, even death if not recognized early enough or left untreated.

5. How to prevent hypoglycemia?

Health care professionals and care teams are essential in helping people not only manage diabetes, but also prevent hypoglycemia. Talk to your care team about developing a personal diabetes management plan based on your goals and lifestyle. It’s important to discuss meal plans, spacing between meals, exercise routines, as well as when your medicine is at its peak level. By developing a plan, you can prevent and manage hypoglycemia.

6. What is the Rule of 15?

The “Rule of 15” is used as a simple guideline for treating hypoglycemia. To follow the “Rule of 15”, after checking your blood glucose level and seeing that it’s under 70 mg/dl, eat 15 grams of carbohydrates or simple sugars, and then recheck your blood sugar level after 15 minutes. If your blood sugar is still low, consume another 15 grams of carbohydrates and recheck again after 15 minutes. Continue to do this until your blood sugar is at your target level, but it would be important to summon help if after two tries, the blood sugar does not go up.

To avoid another low, eat a meal or snack when your blood sugar is back to normal.

7. What are the signs and symptoms of hypoglycemia?

Part of being prepared for a hypoglycemic episode is knowing the signs and symptoms so you can act fast. Typically, these symptoms can range from mild to more severe.

Milder symptoms include:

  • Nausea and dizziness
  • Fast heartbeat
  • Sweating and/or chills
  • Clamminess
  • Unusual irritability or moodiness

Severe symptoms include:

  • Blurred or impaired vision
  • Coordination problems or clumsiness
  • Tingling or numbness in the lips, tongue,or cheeks
  • Color draining from the skin
  • Confusion
  • Seizures

If you experience any hypoglycemic episodes, be sure to share your symptoms and the frequency with your care team.

8. Do you need a prescription for emergency glucagon and who should administer it?

Glucagon is available only by prescription and should be discussed with your care team to see if it's an appropriate option for you.  Traditionally, glucagon has been available as an injectable solution that requires reconstitution, but now also is available as a nasal spray. In the event of a severe hypoglycemic episode, you may not be able to administer the glucagon yourself, so having trained support can save your life. Educate your support circle on how to administer your glucagon and the importance of calling for emergency medical help right away. A detailed instruction for glucagon is provided by the manufacturing company.

9. How to treat hypoglycemia?

Once you become aware that you are experiencing a hypoglycemia emergency, it’s important to know what actions to take.

For Milder Emergencies

  • Follow the “Rule of 15” by eating 15 grams of carbohydrates or simple sugars, and then rechecking your blood sugar level after 15 minutes. If your blood sugar is still low, consume another 15 grams of carbohydrates and recheck again after 15 minutes. Continue to do this until your blood sugar is at your target level. To avoid another low, eat a meal or snack when your blood sugar is back to normal. Remember, you may need to activate emergency medical services if your blood sugar fails to increase despite two tries of the Rule of 15.

For Severe Emergencies

  • Administer emergency hypoglycemia rescue therapy via any delivery method of glucagon (e.g. injected or via nasal spray - available by prescription only). Do not inject insulin, which will lower a person's blood sugar more. If needed, transport the hypoglycemic person to the hospital or call for medical assistance immediately.

10. Should you carry a hypoglycemia rescue kit everywhere you go?

Yes, you can never be too prepared when it comes to hypoglycemia. Carrying a hypoglycemia rescue kit can save your life. This kit could contain candy, juice, sugar or medication such as glucagon (e.g. injected or via nasal spray). Your rescue kit can be travel size for easy carry on and should be taken with you everywhere you go. Speak with your care team about the necessary items you should always have with you.

11. Should your family, friends and close co-workers know if you have hypoglycemia?

It is important to tell your family, friends, and support circle, including close co-workers, that you have hypoglycemia in the event of an emergency.

Educate your support circle about:

  • The common signs and symptoms of hypoglycemia
  • How to monitor your blood sugar levels
  • How to treat hypoglycemia
  • How and when to administer emergency hypoglycemia rescue therapy

Be sure to also tell your support circle to call for medical assistance immediately if you are experiencing a severe hypoglycemic episode. By educating your support circle, they will be prepared, and you will have peace of mind knowing you are not alone in the event of an emergency.


For more information on hypoglycemia and tools to help you talk to your health care professional, please visit our Lowdown on Low Blood Sugar page here.

Help raise awareness by sharing the resources below with your friends and family. It can save your life.

  • Hypoglycemia video playlist - available in both English and Spanish.
  • Everything you need to know about hypoglycemia infographic




Javier Morales, MD, FACP, FACE