Feline hyperaldosteronism is a disease in cats. The symptoms are caused by abnormally high concentrations of the hormone aldosterone, which is secreted by the adrenal gland. The high concentrations of aldosterone may be due directly to a disorder of the adrenal gland (primary hyperaldosteronism), or due to something outside of the adrenal gland causing it to secrete excessive aldosterone (secondary hyperaldosteronism).