Which condition is characterized by hypertension, hypernatremia, and metabolic alkalosis with a renin-aldosterone ratio less than 0.015?

The condition characterized by hypertension, hypernatremia, and metabolic alkalosis with a renin-aldosterone ratio of less than 0.015 is Conn's syndrome, also known as primary hyperaldosteronism. In this condition, the adrenal glands produce excessive aldosterone, leading to sodium retention (hypernatremia) and potassium excretion, which can result in hypokalemia. The excess aldosterone causes sodium retention and promotes water retention, contributing to hypertension.

The important point regarding the renin-aldosterone ratio is that in primary hyperaldosteronism, the renin level is typically suppressed due to the increased blood volume and sodium levels that result from the effects of excess aldosterone. A renin-aldosterone ratio lower than 0.015 suggests that the aldosterone levels are disproportionately high relative to renin levels, which further supports a diagnosis of Conn's syndrome.

Understanding this background lays the groundwork for recognizing why the abnormal laboratory values fit this diagnosis distinctly, as opposed to other conditions that may present with similar hypertension but do not show the specific biochemistry associated with Conn's syndrome.