Final answer:
In primary hyperaldosteronism, the aldosterone level is elevated and the renin level is low or undetectable due to adrenal gland abnormalities. This condition is caused by either an adenoma or hyperplasia, resulting in increased sodium reabsorption, water retention, and elevated blood pressure.
Step-by-step explanation:
In primary hyperaldosteronism, the aldosterone level is elevated and the renin level is low or undetectable. This condition is caused by adrenal gland abnormalities, specifically either an adenoma or hyperplasia. The excess production of aldosterone from the abnormal adrenal gland(s) leads to increased sodium reabsorption, water retention, and an increase in blood pressure.