Which hormonal imbalance may be caused by untreated Diabetes Insipidus?

In the context of Diabetes Insipidus (DI), the primary issue revolves around the body's inability to properly retain water, primarily due to a deficiency in antidiuretic hormone (ADH), also known as vasopressin. ADH is produced in the hypothalamus and released from the posterior pituitary gland. Its main function is to regulate the body’s water balance by promoting the reabsorption of water in the kidneys.

In untreated Diabetes Insipidus, the lack of ADH leads to significant water loss through the urine, resulting in extreme thirst and the excretion of large volumes of dilute urine. Therefore, one would find that the levels of antidiuretic hormone are low due to the underlying condition causing DI, resulting in the correct answer being the low level of ADH.

Understanding this mechanism is crucial as it illustrates how the pathways for water retention and balance in the body are disrupted when ADH is absent or insufficient. This lack of proper hormonal action directly causes the clinical features associated with Diabetes Insipidus, reinforcing the importance of ADH in maintaining hydration and proper kidney function.