Which of the following is a sign of hyperglycemia in a diabetic patient?

Frequent urination is a classic sign of hyperglycemia, particularly in diabetic patients. When blood sugar levels are high, the kidneys work to filter out the excess glucose. This process requires more water, resulting in increased urine production. As a consequence, individuals often find themselves needing to urinate more frequently.

In addition to frequent urination, hyperglycemia can also lead to other symptoms, including increased thirst and fatigue, but the option of frequent urination directly reflects the physiological response to elevated glucose levels.

The other options do not accurately describe the signs of hyperglycemia. Increased appetite might occur with fluctuations in blood sugar but is not a direct indicator of hyperglycemia. Increased energy is generally not associated with high blood sugar, as excessive glucose can lead to fatigue instead. Reduced thirst is contrary to one of the primary symptoms of hyperglycemia, which is increased thirst due to dehydration from frequent urination.