5. Low Blood Glucose (Hypoglycemia)

Hypoglycemia, also known as low blood glucose (blood sugar), is when your blood glucose levels have fallen low enough that you need to take action to bring them back to your target range. This is usually when your blood glucose is less than 70 mg/dL. However, talk to your doctor about your own blood glucose targets, and what level is too low for you.

When can it happen?

Low blood glucose can happen if you’ve skipped a meal or snack, eaten less than usual, or been more physically active than usual. If you don’t take steps to bring glucose levels back to normal, you could even pass out.

What are the symptoms?

Each person’s reaction to low blood glucose is different. It’s important that you learn your own signs and symptoms when your blood glucose is low.

Signs and symptoms of low blood glucose include:

  • Feeling shaky
  • Being nervous or anxious
  • Sweating, chills, clamminess
  • Mood swings, irritability, impatience
  • Confusion
  • Fast heartbeat
  • Feeling light-headed or dizzy
  • Hunger, nausea
  • Color draining from skin (pallor)
  • Feeling sleepy
  • Feeling weak, having no energy
  • Blurred/impaired vision
  • Tingling or numbness in lips, tongue, cheeks
  • Headaches
  • Coordination problems, clumsiness
  • Nightmares or crying out in sleep
  • Seizures

What should you do?

The 15-15 rule—have 15 grams of carbohydrate to raise your blood glucose and check it after 15 minutes. If it’s still below 70 mg/dL, have another serving.

Repeat these steps until your blood glucose is at least 70 mg/dL. Once your blood glucose is back to normal, eat a meal or snack to make sure it doesn’t lower again.

This may be:

  • Glucose tablets (see instructions)
  • Gel tube (see instructions)
  • 4 ounces (1/2 cups) of juice or regular soda (not diet)
  • 1 tablespoon of sugar, honey, or corn syrup
  • 8 ounces of nonfat or 1% milk
  • Hard candies, jellybeans, or gumdrops—see food label for how many to consume

Make a note about any episodes of low blood glucose and talk with your health care team about why it happened. They can suggest ways to avoid low blood glucose in the future.

Your doctor may refer to different levels of hypoglycemia. These include:

  • Level 1—blood glucose between 54 and 70 mg/dL
  • Level 2—blood glucose less than 54 mg/dL
  • Level 3—when you need help to treat your low blood glucose.

Severe hypoglycemia

When low blood glucose isn’t treated and you need someone to help you recover, it is considered a severe event.

Treating Severe Hypoglycemia

Glucagon is a hormone produced in the pancreas that stimulates your liver to release stored glucose into your bloodstream when your blood glucose levels are too low. Injectable glucagon is used to treat someone with diabetes when their blood glucose is too low to treat using the 15-15 rule.

Glucagon kits are available by prescription. Speak with your doctor about whether you should buy a glucagon kit and how and when to use it.

The people you are in frequent contact with (for example, friends, family members, and coworkers) should be instructed on how to give you glucagon to treat severe hypoglycemia.

Steps for treating a person with symptoms keeping them from being able to treat themselves.

  1. Inject glucagon into the buttock, arm, or thigh, following the instructions in the kit.
  2. When the person regains consciousness (usually in 5-15 minutes), they may experience nausea and vomiting.
  3. If you have needed glucagon, let your doctor know so you can discuss ways to prevent severe hypoglycemia in the future.


  • Inject insulin (it will lower their blood glucose even more)
  • Provide food or fluids (they can choke)
  • Put hands in mouth (they can choke)

Don’t hesitate to call 911. If someone is unconscious and glucagon is not available or someone does not know how to use it, call 911 immediately.

Content courtesy of the American Diabetes Association.

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