Which symptom may indicate the presence of hypoglycemia?

Altered level of consciousness is a key symptom that may indicate hypoglycemia because low blood sugar levels can significantly affect brain function. The brain relies heavily on glucose as its primary source of energy, and when glucose levels drop, it can lead to confusion, dizziness, disorientation, and even loss of consciousness. These neurological effects occur because the brain does not receive the necessary fuel it requires to function properly.

While other symptoms like hyperactivity, severe headache, or elevated heart rate can be associated with various conditions, they are not typically indicative of hypoglycemia. Hyperactivity is more common in situations of elevated blood sugar or stimulant use, and a severe headache can be caused by numerous factors, including dehydration or tension. An elevated heart rate can occur due to many reasons, including anxiety or stress, but alone does not specifically signify hypoglycemia. Thus, an altered level of consciousness serves as a more direct indicator of critically low blood sugar levels and requires immediate attention to avoid further complications.