Episodes nearly always occur in the morning after an overnight
fast, often one that is longer than usual. Symptoms include those of neuroglycopenia,
ketosis, or both. The neuroglycopenic symptoms usually include lethargy and malaise, but may include unresponsiveness or seizures. The principal symptoms of ketosis are anorexia, abdominal discomfort, and nausea, sometimes progressing to vomiting.
If severe, parents usually take the child to a local emergency department, where blood is drawn.