genitourinary disorders
Polyuria
Key Points
Use of diuretics and uncontrolled diabetes mellitus are common causes of polyuria. In the absence of diabetes mellitus and diuretic use, the most common causes of chronic polyuria are primary polydipsia, central diabetes insipidus, and nephrogenic diabetes insipidus. Hypernatremia can indicate central or nephrogenic diabetes insipidus. Hyponatremia is more characteristic of polydipsia. Abrupt onset of polyuria suggests central diabetes insipidus. A water deprivation test can help with diagnosis but should only be done with the patient under close supervision. 