Which of the following is a symptom of hyperglycemia?

Increased thirst is a classic symptom of hyperglycemia, which occurs when there is an excess of glucose in the bloodstream. When blood sugar levels rise, the kidneys work to filter out the excess glucose. This process requires more water, leading to increased urine production. As the body loses more fluid through frequent urination, it signals a need for more hydration, resulting in thirst. This symptom is part of the body's attempt to restore balance and prevent dehydration caused by high blood sugar levels.

The other symptoms listed do not directly relate to hyperglycemia in the same way. Severe dizziness can occur in a variety of conditions, including hypoglycemia (low blood sugar), and is not a primary indicator of hyperglycemia. Frequent weight loss can be associated with uncontrolled diabetes but is a more chronic symptom and not specifically indicative of hyperglycemia. Excessive sweating is typically related to other conditions or stress responses and not a direct result of elevated blood sugar levels. Therefore, increased thirst is the most relevant and immediate symptom associated with hyperglycemia.