A patient with Addison's disease typically presents with which type of electrolyte imbalance?

Addison's disease, also known as primary adrenal insufficiency, is characterized by the adrenal glands' inability to produce sufficient amounts of cortisol and aldosterone. This deficiency leads to specific electrolyte imbalances.

The correct choice reflects the typical laboratory findings in someone with Addison's disease, which include low sodium (hyponatremia) and high potassium (hyperkalemia). The low sodium occurs due to inadequate aldosterone secretion, which normally promotes sodium reabsorption in the kidneys. When aldosterone levels are low, sodium is lost in the urine, leading to decreased serum sodium levels.

Simultaneously, the lack of aldosterone also causes an inability to excrete potassium effectively. This results in elevated potassium levels in the bloodstream. Patients with Addison's disease may present with symptoms related to these imbalances, such as fatigue, muscle weakness, and fluctuations in blood pressure.

Thus, the characteristic electrolyte pattern of low sodium and high potassium is what defines Addison's disease, making the choice that reflects this imbalance accurate.