This type of benign adrenal tumor produces too much of the hormone aldosterone and causes a condition called Conn syndrome, or hyperaldosteronism, which raises blood pressure and lowers potassium level.

In addition to high blood pressure that’s difficult to bring under control, aldosteronomas may cause a feeling of overall weakness, unusually intense thirst or urination, and a low level of potassium and high level of salt in the blood.

Bilateral adrenal hyperplasia, or BAH, is another common cause of Conn syndrome. BAH causes both adrenal glands to produce too much aldosterone even though no tumor is present.