What is a common side effect of hyperglycemia that affects urination?

Polyuria is a common side effect of hyperglycemia and refers to the production of an excessive amount of urine. This occurs because high blood sugar levels lead to increased glucose in the urine, which in turn draws water out of the body through osmotic diuresis. When glucose spills into the urine, it raises the osmolarity of the urine, causing the kidneys to excrete more water to dilute the glucose, resulting in frequent urination.

In contrast, oliguria, which refers to a decreased urine output, is not associated with hyperglycemia but rather with conditions such as kidney dysfunction or dehydration. Urinary retention involves an inability to empty the bladder completely and is unrelated to high blood sugar levels. Hematuria, or blood in the urine, can have various causes but is not a typical consequence of hyperglycemia. Thus, polyuria is the expected outcome when blood glucose levels are elevated, making it the correct choice.