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Hypoglycemia and low blood sugar

  • Glucose is a form of sugar that comes from carbohydrates found in foods, and is a main source of fuel for all of the cells of the body and, especially, the brain. While the body is quite good at extracting glucose from the foods we eat, it relies on a hormone called insulin to actually get the glucose inside the cells of specific organs: the liver, fat, and muscle.

    We can think of insulin as holding the “key” to acell– without insulin, the glucose just remains in the blood, where it’s alsoknown as “blood sugar.” During an episode of hypoglycemia, the blood sugar level is too low (there’s not enough glucose in the blood) to effectively fuel the body’s cells.

    • It can be helpful to think of hypoglycemia as something that happens in episodes, rather than as a permanent condition.

    • Hypoglycemia is most common in newborns. 

    • In older children, it’s most often seen as a complication of insulin therapy for diabetes, but can sometimes have other causes as well.

    • In the majority of cases, hypoglycemia is temporary, easily treated, and usually does not have serious consequences.

    • There are several rare disorders in which hypoglycemia is recurrent and potentially life-threatening. However, with timely diagnosis and appropriate treatment, these can be effectively managed.

    How Children’s Hospital Boston approaches hypoglycemia

    At Children’s, we treat hypoglycemia in our General Endocrinology Program a multi-disciplinary program dedicated to the treatment of a wide range of endocrinological disorders.

    Caring for more than 7,000 patients each year, our division is one of the largest pediatric endocrinology practices in the country. We provide state-of-the-art diagnosis, treatment and clinical management for children with hypoglycemia and related disorders.

    For more than three decades, the investigation and treatment of hypoglycemia disorders in infancy and childhood has been a major clinical and research interest of the Division of Endocrinology.

    Endocrinology

    Boston Children's Hospital
    300 Longwood Avenue
    Boston MA 02115


     617-355-7476

  • What is hypoglycemia?

    Hypoglycemia is the state of having a blood glucose (also known as blood sugar) level that is too low to effectively fuel the body's cells.

    What is glucose?

    Glucose is a sugar that’s derived from the breakdown of carbohydrates found in foods, and the main source of fuel for the body (including the brain). It may be stored in the liver and muscles for later use, but excess glucose is converted to fat. The level of glucose in the blood is regulated by complex hormonal and neurologic mechanisms.

    What is a healthy range of blood glucose?

    The normal range of blood glucose throughout the day and night is approximately 70 to 150 mg/dl (milligrams of glucose per deciliter of blood). However, this varies according to a number of factors; your child’s doctor will talk with you about what should be a normal range for him.

    Why is hypoglycemia a concern?

    The brain depends on glucose, and too little can impair its ability to function. Severe or prolonged hypoglycemia could result in seizures and serious brain injury.

    Causes

    The vast majority of episodes of hypoglycemia in children and adolescents occur when a child with diabetes takes too much insulin and/or eats too little or exercises strenuously or for a prolonged period of time.

    For young children who do not have diabetes, hypoglycemia may be caused by:

    Single episodes:

    • Stomach flu, or another illness that may cause them to not eat enough
    • fasting for a prolonged period of time
    • prolonged strenuous exercise and lack of food

    Recurrent episodes:

    • accelerated starvation, also known as “ketotic hypoglycemia”
    • medications your child may be taking
    •  a congenital (present at birth) error in metabolism or unusual disorder such as hypopituitarism or hyperinsulinism.

    Other causes of hypoglycemia in children are rare.

    What is accelerated starvation?

    While accelerated starvation has a serious-sounding name, it simply refers to a tendency for children without diabetes or any other known cause of hypoglycemia to experience repeated hypoglycemic episodes.

    Accelerated starvation usually first appears when a child is between 18 months and 5 years old. Children with accelerated starvation are more likely than others to experience hypoglycemia during illness, after having fasted (overnight, for example) and after strenuous exercise. They may be small and thin for their age, and have less muscle mass than their peers.

    Treatment for accelerated starvation is simply making sure that your child avoids prolonged periods of fasting. Give him frequent, small meals and snacks, especially before bedtime and whenever the child has not eaten a heart supper. The condition usually disappears on its own by the time the child is 8 or 9 years old.

    Symptoms of hypoglycemia in children

    While each child may experience symptoms of hypoglycemia differently, the most common include:

    • shakiness
    • dizziness
    • sweating
    • hunger
    • headache
    • irritability
    • pale skin color
    • sudden moodiness or behavior changes, such as crying for no apparent reason
    • clumsy or jerky movements
    • difficulty paying attention, or confusion
    • tingling sensations around the mouth

    FAQ

    Q: Will my child be okay?

    A: Most likely yes. Hypoglycemia is serious, but usually not life-threatening.

    Q: How could hypoglycemia affect my child’s health?

    A: The brain depends on glucose, and too little can impair its ability to function. Severe or prolonged hypoglycemia could result in seizures and permanent brain injury.

    Q: What causes hypoglycemia?

    A: Most episodes of hypoglycemia in children and adolescents occur when a child with diabetes takes too much insulin and/or eats too little.

    For children who do not have diabetes, hypoglycemia may be caused by:

    Single episodes:

    • stomach flu, or another illness that may cause them to not eat enough
    • fasting for a prolonged period of time
    • prolonged strenuous exercise and lack of food

    Recurrent episodes:

    • accelerated starvation, also known as “ketotic hypoglycemia”
    • medications your child may be taking
    • a congenital (present at birth) error in metabolism or unusual disorder such as hypopituitarism or hyperinsulinism.

    Q: How long will it take my child to recover from hypoglycemia?

    A: This depends entirely on the severity of the episode. If your child’s hypoglycemia is not severe, he should feel better within 10 to 15 minutes of eating or drinking something.

    Q: Can hypoglycemia be prevented?

    A: This depends on the cause, but many episodes of hypoglycemia can be prevented by making sure your child eats frequent meals and snacks throughout the day and has something to eat before going to bed. If your child eats little at dinner, a hearty snack before bedtime (such as a glass of milk and peanut butter on toast) will keep his blood sugar levels stable throughout the night.

  • How can doctors tell if my child has hypoglycemia?

    If your child has diabetes, hypoglycemia is usually caused by insulin reaction, a common complication of diabetes.

    For children who have symptoms of hypoglycemia and don’t have diabetes, in addition to a complete medical history and physical exam, your child’s physician will look for evidence of what’s known as the Whipple Triad:

    • symptoms known or likely to be caused by hypoglycemia
    • low plasma glucose measured at the time of the symptoms
    • relief of symptoms when glucose is raised to normal

    The doctor may also order laboratory tests to measure your child’s insulin production.

  • Children with hypoglycemiahave different symptoms, and these vary from one child to another. But no matter what your child’s symptoms, the overriding goal is the same: to bring her blood sugar back up to normal as rapidly as possible and return her to good health.

    How is hypoglycemia treated?

    Most often, your child’s blood sugar can be brought back up to normal by having him eat or drink something that has sugar in it, such as fruit juice, regular soda, table sugar, maple syrup, candy (e.g., Skittles), glucose tablets, glucose gel, cake frosting.Consider encouraging your child to:

    • eat regular meals throughout the day
    • eat frequent snacks

    For children with diabetes, the goal is to consistently maintain a blood sugar level that is in a healthy range. This involves testing blood sugar often, learning to recognize the earliest symptoms of low blood sugar and treating the condition quickly, based on instructions given by your child's healthcare providers.

    If your child has recurrent or severe hypoglycemia, the first thing we’ll do is determine the cause, because different causes have different treatments. While we’re determining the cause, some children will receive glucose through intravenously (through an IV) in the hospital to make sure their blood sugar level stays normal.

    We can treat some causes of hypoglycemia with changes in your child’s diet, and/or medication. For some rare cases of severe hypoglycemia that don’t respond to medical treatment, the doctor may recommend surgery to remove most of the pancreas.  

  • Boston Children's Hospital's Division of Endocrinology operates one of the nation's most extensive research programs focused on pediatric endocrine disorders. With more than 50 basic science and clinical researchers, we are attempting to unravel the genetic and biochemical underpinnings of the endocrine system.

    Specific projects we’re exploring include:

    • improving treatment of diabetes by harnessing the power of the internet to improve communication between patients and their medical caregivers.

    • research aimed at finding genes that cause diabetes and its complications.

    • gene therapy strategies for rare metabolic disorders such as glycogen storage disease

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