What happens if blood glucose levels are too high?

When blood glucose levels are too high, a condition known as hyperglycemia occurs. This state can lead to various physiological effects, including lethargy and sluggishness. High glucose concentrations can disrupt normal cellular functions and energy utilization, causing the body to feel fatigued and less efficient.

In contrast, while other options relate to possible health impacts from high glucose levels, they do not summarize the immediate feelings a person might experience. For example, kidney issues or enzyme problems are more associated with prolonged hyperglycemia rather than acute responses. Similarly, fainting is not a direct consequence of high glucose levels; it could stem from various factors but is not typical in initial hyperglycemic conditions.

Therefore, the correct choice reflects a direct and common symptom experienced by individuals with elevated blood glucose levels, highlighting the sluggishness and fatigue that can accompany this metabolic disturbance.