What is a characteristic urinary finding in patients with Addison's disease?

In patients with Addison's disease, a characteristic urinary finding is decreased urine sodium. This condition is due to adrenal insufficiency, leading to a deficiency in cortisol and aldosterone. Aldosterone plays a critical role in regulating sodium and potassium balance in the body; when its levels are inadequate, the kidneys do not reabsorb sodium effectively, leading to a loss of sodium in the urine. As a result, patients often present with hyponatremia, which is reflected by the decreased sodium levels in the urine.

This decreased urine sodium can also contribute to other clinical manifestations such as hypotension and fatigue, as the body struggles to maintain its electrolyte balance and blood volume. The maintenance of sodium is crucial for many bodily functions, including fluid balance and blood pressure regulation. Therefore, the presence of low urine sodium aligns with the pathophysiological processes occurring in Addison's disease, highlighting its importance as a characteristic finding in the condition.