Ketotic hypoglycemia is a condition of low blood sugar (hypoglycemia) that occurs with high levels of ketones in the blood or urine. It is the most common cause of low blood sugar in children between 18 months and 5 years old. This condition is not related to diabetes.
Causes and Common Triggers
The cause of ketotic hypoglycemia relates to how a child’s body uses and stores energy. A child’s body uses glucose (sugar) for energy, which is stored in the liver as glycogen. After a period without food, such as overnight, these glycogen stores can be used up. The body then breaks down fat for energy, producing molecules called ketones. In children susceptible to this condition, this switch is accompanied by a drop in blood sugar levels.
This response can be triggered by fasting, especially when a child misses a meal. Illnesses that cause a poor appetite, vomiting, or diarrhea can also lead to an episode by depleting energy reserves more quickly. Another trigger is high physical activity without consuming enough food to compensate, as smaller body size and lower fat stores make children more prone to these episodes.
Recognizing the Symptoms
Symptoms of ketotic hypoglycemia often appear in the morning after an overnight fast. Early signs can be subtle and may be mistaken for typical toddler behavior, including paleness, sudden irritability, sweating, and feeling shaky. A child might also complain of a headache, feel dizzy, or seem unusually tired and lethargic.
As blood sugar levels drop further, more significant symptoms may develop. The child might become confused, clumsy, or have difficulty thinking clearly. In some cases, parents may notice a distinct, fruity smell on their child’s breath, which is the odor of ketones. Severe episodes can lead to unresponsiveness or seizure-like activity, which requires immediate medical attention.
Diagnosis and Medical Evaluation
A diagnosis of ketotic hypoglycemia is confirmed when a specific set of criteria is met. This includes the simultaneous presence of low blood glucose (below 70 mg/dL), ketones in the blood or urine, and a rapid improvement in symptoms after the child is given sugar. To confirm this, a doctor will perform blood and urine tests during a symptomatic episode, often in an emergency department.
The medical evaluation also serves to rule out other health conditions that can cause similar symptoms. Laboratory tests may measure hormones like insulin, growth hormone, and cortisol to ensure other metabolic processes are functioning as expected.
Management and Prevention Strategies
Immediate Treatment
During an episode of hypoglycemia, the immediate goal is to raise the child’s blood sugar level quickly. This is accomplished by giving the child a source of fast-acting sugar, such as fruit juice, regular soda, or glucose tablets. A carbohydrate-rich snack can also be effective, with improvement often seen within 15 to 20 minutes.
If a child is too lethargic to swallow, is vomiting, or has severe symptoms like seizures, they require emergency medical care. In a hospital, medical staff can administer glucose through an intravenous (IV) line. Learning to recognize the early signs is an important step for parents to prevent a more serious event.
Long-Term Prevention
Preventing future episodes involves dietary strategies designed to avoid long periods without food. Providing regular meals and snacks throughout the day is a primary strategy. Offering a bedtime snack that is rich in both protein and complex carbohydrates helps to maintain stable blood glucose levels overnight.
For some children, a doctor might recommend a specific bedtime snack of uncooked cornstarch mixed in a drink or food. Uncooked cornstarch is digested very slowly, providing a steady release of glucose over several hours. This approach should only be implemented under the guidance of a healthcare professional. Most children naturally outgrow ketotic hypoglycemia by the time they are six to nine years old as their bodies develop a greater capacity to store and manage energy.