What is a common symptom of hyperglycemia in a diabetic patient?

Fatigue is indeed a common symptom of hyperglycemia in diabetic patients. When blood sugar levels are elevated, the body often struggles to utilize glucose effectively for energy. This can lead to a lack of sufficient energy at the cellular level, resulting in feelings of tiredness and lethargy. Additionally, hyperglycemia can lead to dehydration as excess glucose in the bloodstream prompts the kidneys to excrete more urine, which can further contribute to fatigue.

In considering the context of the other options, increased sweating is typically associated with hypoglycemia rather than hyperglycemia. Weight gain may not directly correlate with hyperglycemia in the short term, as prolonged high blood sugar can sometimes lead to weight loss if insulin levels are not sufficient. Decreased thirst is also not associated with hyperglycemia; in fact, increased thirst is a common symptom linked with elevated blood sugar levels, as the body attempts to counteract dehydration. Thus, fatigue stands out as the significant symptom of hyperglycemia in this context.