What is low blood sugar in diabetes?

Hypoglycemia: Overview

Hypoglycemia means that your blood sugar is low and your body is not getting enough fuel. Some people get low blood sugar from not eating often enough. Some medicines to treat diabetes can cause low blood sugar. People who have had surgery on their stomachs or intestines may get hypoglycemia. Problems with the pancreas, kidneys, or liver also can cause low blood sugar.

A snack or drink with sugar in it will raise your blood sugar and should ease your symptoms right away.

Your doctor may recommend that you change or stop your medicines until you can get your blood sugar levels under control. In the long run, you may need to change your diet and eating habits so that you get enough fuel for your body throughout the day.

Diabetic Hypoglycemia

Diabetic hypoglycemia (also called insulin shock or insulin reaction) is having an abnormally low amount of sugar (glucose) in the blood relative to the amount of insulin in the blood.

A person with diabetes can become hypoglycemic by taking too much insulin or diabetes medicine or by skipping meals.

Symptoms of hypoglycemia include headache, hunger, weakness, sweating, anxiety, and changes in personality. If untreated, it can lead to seizures, unconsciousness, brain damage, or death.

Treatment for diabetic hypoglycemia involves eating foods that contain sugar or getting a dose of glucagon. This is a substance that stimulates the liver to release glucose into the bloodstream.

What are the symptoms of low blood sugar?

If your blood sugar drops below 70 mg/dL, you may have symptoms of mild low blood sugar, such as:

  • Sweating (almost always present).
  • Feeling nervous, shaky, and weak.
  • Extreme hunger and slight nausea.
  • Dizziness and headache.
  • Blurred vision.
  • Fast heartbeat.

If you have had diabetes for many years, you may not always have symptoms of mild low blood sugar.

If your blood sugar continues to drop, your behavior may change. Symptoms of moderate low blood sugar may include:

  • Inability to concentrate.
  • Confusion and irritability.
  • Slurred speech.
  • Unsteadiness when standing or walking.
  • Muscle twitching.
  • Personality changes, such as anger or crying.

Severe low blood sugar may cause:

  • Seizure.
  • Loss of consciousness (coma).
  • Stroke.
  • Death.

How is low blood sugar (hypoglycemia) in diabetes treated?

You can treat low blood sugar by eating or drinking something that has 15 grams of carbohydrate. These should be quick-sugar foods. Check your blood sugar level again 15 minutes after having a quick-sugar food to make sure your level is getting back to your target range.

Children usually need less than 15 grams of carbohydrate. Check with your doctor or diabetes educator for the amount that is right for your child.

Here are examples of quick-sugar foods that have 15 grams of carbohydrate:

  • 3 to 4 glucose tablets
  • 1 tablespoon (3 teaspoons) of table sugar
  • 1 tablespoon (3 teaspoons) honey
  • ½ cup to ¾ cup (4 to 6 ounces) of fruit juice or regular (not diet) soda
  • Hard candy (such as 6 Life Savers)

If you have problems with severe low blood sugar, someone else may have to give you glucagon. This is a hormone that raises blood sugar levels quickly.

How can you prevent low blood sugar (hypoglycemia) in diabetes?

You can take steps to prevent low blood sugar.

  • Follow your treatment plan. Take your insulin or other diabetes medicine exactly as your doctor prescribed it. Talk with your doctor if you're having low blood sugar often. Your medicine may need to be adjusted if it's causing your low blood sugar.
  • Check your blood sugar levels often. This helps you find early changes before an emergency happens.
  • Keep a quick-sugar food with you in case your blood sugar level drops low.
  • Eat small meals more often so that you don't get too hungry between meals. Don't skip meals.
  • Balance extra exercise with eating more. Check your blood sugar and learn how it changes after exercise. If your blood sugar stays at a normal level, you may not need to eat after you exercise.
  • Limit how much alcohol you drink. Alcohol can make low blood sugar go even lower. Don't drink alcohol if you have problems recognizing the early signs of low blood sugar.
  • Keep a diary of your symptoms. This helps you learn when changes in your body may signal low blood sugar. And keep track of how often you have low blood sugar, including when you last ate and what you ate. This will help you learn what causes your blood sugar to drop.
  • Learn about diabetes and low blood sugar. Support groups or a diabetes education center can help you understand how medicines, diet, and exercise affect your blood sugar levels.

Since low blood sugar levels can quickly become an emergency, be sure to wear medical alert jewelry, such as a medical alert bracelet. This is to let people know you have diabetes so they can get help for you. You can buy this at most drugstores. And make sure your family, friends, and coworkers know the symptoms of low blood sugar. Teach them what to do to get your sugar level up.

How is frequent low blood sugar diagnosed when you have diabetes?

If your blood sugar is often lower than your target range, your doctor may ask about your diabetes medicine, such as how much you take and when you take it. You may be asked about when you eat and exercise. The doctor might ask about other medicines you take that could affect blood sugar.

How can you care for yourself when you have hypoglycemia?

  • Learn your signs of low blood sugar. They are different for everyone. Some common early signs include:
    • Nausea.
    • Hunger.
    • Feeling nervous, irritable, or shaky.
    • Cold, clammy skin.
    • Sweating (when you're not exercising).
  • Use the "rule of 15" to treat low blood sugar. This includes eating 15 grams of carbohydrate from a quick-sugar food, such as 3 or 4 glucose tablets or ½ cup of juice. Wait 15 minutes and check your blood sugar. If it is still below 70 mg/dL, eat another 15 grams of carbohydrate. Repeat this every 15 minutes until your blood sugar is in a safe target range.
  • Once your blood sugar is in a safe range, eat a snack or meal to prevent recurrent low blood sugar.
  • Make sure family, friends, and coworkers know the symptoms of low blood sugar and know how to get your sugar level up.
  • If you were prescribed glucagon, always have it with you. Make sure friends and family know how to use it.

What is low blood sugar (hypoglycemia) in diabetes?

Hypoglycemia means that your blood sugar is low and your body (especially your brain) is not getting enough fuel. If you have diabetes, your blood sugar can go too low if you take too much of some diabetes medicines. It can also go too low if you miss a meal. And it can happen if you exercise too hard without eating enough food. Some medicines used to treat other health problems can cause low blood sugar too.

What can cause low blood sugar (hypoglycemia) when you have diabetes?

You're not likely to get low blood sugar unless you take insulin or certain diabetes pills that lower blood sugar. Then it may happen if you:

  • Take too much diabetes medicine in a day, take your doses too close together, or take your full dose of medicine when you aren't going to eat your usual amount of food.
  • Exercise too much without eating enough food.
  • Skip a meal.
  • Drink too much alcohol, especially on an empty stomach.
  • Take other medicines that can lower blood sugar as a side effect.
  • Have problems with your kidneys or liver.

How can you treat low blood sugar?

If you're taking diabetes medicine, you can have problems with low blood sugar. These symptoms include:

  • Sweating.
  • Feeling weak.
  • Feeling shaky.
  • Feeling very hungry.

If you have symptoms of low blood sugar, check your blood sugar. To treat low blood sugar, eat or drink a quick-sugar food that has about 15 grams of carbohydrate. Your goal is to get your level back to your safe range.

Children usually need less than 15 grams of carbohydrate. Check with your doctor or diabetes educator for the amount that is right for your child.

Check your blood sugar again 15 minutes later. If it's still not in your target range, take another 15 grams of carbohydrate and check your blood sugar again in 15 minutes.

Repeat this until you reach your target. Then go back to your regular testing schedule.

When you have low blood sugar, it's best to stop or reduce any physical activity until your blood sugar is back in your target range and is stable.

If you must stay active, eat or drink 30 grams of carbohydrate. Then check your blood sugar again in 15 minutes. If it's not in your target range, take another 30 grams of carbohydrates. Check your blood sugar again in 15 minutes. Keep doing this until you reach your target. You can then go back to your regular testing schedule.

If your symptoms or blood sugar levels are getting worse or have not improved after 15 minutes, seek medical care right away.

Here are some examples of quick-sugar foods with 15 grams of carbohydrate:

  • 3 or 4 glucose tablets
  • 1 tablespoon (3 teaspoons) table sugar
  • ½ to ¾ cup (4 to 6 oz) of fruit juice or regular (not diet) soda
  • Hard candy (such as 6 Life Savers)

Hypoglycemia: When to call

Call 911 anytime you think you may need emergency care. For example, call if:

  • You passed out (lost consciousness).
  • You are confused or cannot think clearly.
  • Your blood sugar is very high or very low.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • Your blood sugar stays outside the level your doctor set for you.
  • You have any problems.

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