Hypoglycemia refers to when blood sugar levels drop too low. Generally, experts consider blood sugar levels at or below 50 mg/dL dangerous.

Low blood sugar levels, or hypoglycemia, describes when blood glucose levels fall below a healthy range. Glucose is the body’s main energy source and is essential for the proper functioning of every organ system. As such, it is important to maintain blood sugar levels within a healthy range.

Hypoglycemia may occur due to diabetes medications, skipping meals, or very intense exercise. A significant drop in blood glucose levels can result in severe complications, such as seizures and coma.

If a person is at risk of dangerously low blood sugar levels, they should regularly monitor their blood glucose. They can correct their blood sugars using fast-acting carbs, such as glucose tablets. It is also sensible for friends, family, and caregivers to be familiar with the signs of hypoglycemia and know how to administer a glucagon kit in case of a hypoglycemic emergency.

This article explains what blood sugar levels experts consider dangerous. It also lists what to do if sugar levels drop to these levels.

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Generally, health experts consider fasting blood sugar levels at or below 99 milligrams per deciliter (mg/dL) normal.

For individuals living with diabetes, healthcare professionals often provide them with a target range. The American Diabetes Association (ADA) recommends target levels of 80 to 130 mg/dL before eating if a person has diabetes. Within 2 hours of eating a meal, blood glucose levels should be less than 180 mg/dL.

Severe hypoglycemia is a term people may use to describe when blood sugar levels become dangerously low. Generally, guidelines may consider any value around 50 mg/dL or lower to be severe.

When blood sugar levels become too low, a person is at risk of losing consciousness, having a seizure, and falling into a coma. They will require assistance from another individual to help restore their blood glucose to a stable level.

Read more about hypoglycemia.

If a person notices symptoms they associate with low blood sugar, they should check their blood sugar levels.

Symptoms of low blood sugar

Symptoms of hypoglycemia can vary from person to person.

Mild to moderate symptoms of low blood sugar include:

  • jitters or shakes
  • hunger
  • tiredness
  • dizziness or lightheadedness
  • confusion
  • change in heart rate
  • headaches
  • unclear speech

Severe symptoms of low blood sugar include:

  • loss of consciousness
  • seizure

In case of a hypoglycemic event, a person can perform the 15-15 rule to restore blood sugar levels to a suitable range.

This refers to a method of ingesting 15 grams of carbohydrates to increase blood glucose. A person then waits 15 minutes and rechecks their blood sugar level. If necessary, they have another serving of carbs and repeat the method until they reach a suitable level.

However, if a person is experiencing dangerously low blood sugar levels, they may not be able to eat or drink. In this circumstance, a person will typically require an emergency dose of glucagon.

Glucagon is a hormone that can quickly elevate blood sugar levels. It is widely available as a nasal spray or injectable.

Glucagon injection

To administer injectable glucagon:

  1. Insert the needle of the prefilled syringe into the rubber stopper on top of the vial containing glucagon powder.
  2. Push down on the syringe plunger to inject all the liquid from the syringe into the vial.
  3. Without removing the needle, gently mix the vial until the powder dissolves. The solution should be clear, have no particles remaining, and have a water-like consistency.
  4. Draw all the glucagon solution from the vial into the syringe.
  5. Inject the glucagon solution into the person’s thigh, buttock, or upper arm. Use the thumb to push the plunger all the way down.
  6. Remove the syringe, call emergency services, and inform them of the situation.
  7. If the individual does not respond after 15 minutes, a person can administer an additional dose of glucagon while waiting for emergency assistance.
  8. When the individual responds to treatment and can swallow, give them oral carbohydrates to prevent the recurrence of hypoglycemia.

Glucagon nasal spray

To administer nasal glucagon:

  1. Insert the tip of the device into one nostril.
  2. Press the device’s plunger all the way in. Inhalation of the dose is not necessary.
  3. Call for emergency help after administering the dose.
  4. When the individual responds to treatment, give them oral carbohydrates to prevent the recurrence of hypoglycemia.

Hypoglycemia is the medical term for low blood sugar levels. Typically, health experts define hypoglycemia as blood glucose levels less than 70 mg/dL.

However, these values may vary slightly between individuals. A person can consult a doctor to identify what blood sugar level is low for them.

Read more about blood glucose levels.

Hypoglycemia is more common in individuals with type 1 diabetes and those with type 2 diabetes taking certain medications. However, anyone can experience hypoglycemia.

Insulin is a hormone that helps regulate blood sugar levels. People living with diabetes can use insulin to help manage their blood glucose. However, accidentally injecting the wrong insulin type, too much insulin, or injecting directly into the muscle instead of just under the skin can lead to hypoglycemia.

Skipping meals or not consuming enough carbohydrates can also result in low blood sugar levels. Additionally, hypoglycemia can occur following very intense exercise or drinking alcohol.

According to the Centers for Disease Control and Prevention (CDC), tips for managing blood sugar levels can include:

  • following a healthful dietary plan
  • maintaining a moderate weight
  • getting regular exercise
  • regularly monitor blood sugars
  • eating at regular times and not skipping meals
  • tracking meals and physical activity
  • limiting alcoholic beverages

Diabetes resources

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Hypoglycemia describes low blood sugar levels. Health experts typically consider values less than 50 mg/dL to be severely low.

With severe hypoglycemia, a person is at risk of losing consciousness and falling into a coma.

In such situations, they may be unable to eat to restore their blood sugar levels. In these circumstances, a friend, family member, or caregiver may need to administer either injectable or oral glucagon. After administering glucagon, a person should call emergency services and remain with the individual experiencing hypoglycemia.