Which is NOT a symptom associated with diabetes insipidus?

Diabetes insipidus is characterized primarily by a deficiency in the hormone vasopressin (also known as antidiuretic hormone, ADH), which leads to the kidneys being unable to concentrate urine properly. This results in the excretion of large volumes of dilute urine, which is referred to as polyuria. Consequently, as a compensatory mechanism for the excessive urinary water loss, affected individuals often experience intense thirst, leading to polydipsia.

Another important aspect of diabetes insipidus is the potential for hypernatremia, which refers to elevated sodium levels in the blood. This condition can occur due to the loss of free water from the body that leads to a relative increase in serum sodium concentration, particularly if fluid intake does not adequately replace the lost volume.

In contrast, obesity is not a symptom associated with diabetes insipidus. While obesity can be related to other forms of diabetes, such as type 2 diabetes mellitus, it does not typically correlate with the symptoms of diabetes insipidus. The core symptoms of diabetes insipidus revolve around the dysregulation of water balance and the consequent symptoms resulting from excessive urination and thirst, rather than weight gain or obesity.