Which symptom is characteristic of hyperglycemia?

The symptom most characteristic of hyperglycemia is a distinct fruity breath odor, which is often due to the presence of ketones in the blood. When the body has insufficient insulin to adequately process glucose, it begins to use fat for energy. This process produces ketones, which can lead to a condition known as diabetic ketoacidosis, characterized by a sweet or fruity smell on the breath.

This breath odor manifests as a result of the acidic environment created by the accumulation of ketones, making it a specific indicator of hyperglycemic episodes, especially in uncontrolled diabetes. Recognizing this symptom is crucial for timely intervention and management of hyperglycemia, potentially preventing further complications such as diabetic ketoacidosis.