Hyperaldosteronism in Cats

Hyperaldosteronism in cats describes a pattern in which the adrenal glands produce too much of a hormone called aldosterone. Aldosterone helps regulate the balance of sodium and potassium in the blood, and when present in excess, it tends to drive potassium levels down and blood pressure up. The condition arises most often from a small tumour in one or both adrenal glands, though in some cats the cause remains unclear. Owners may notice increased thirst and urination, occasional weakness or a stiff, stilted gait, or sometimes no outward signs at all—the pattern may only come to light during blood tests taken for other reasons. Muscle weakness, when present, often reflects the low potassium levels that result from aldosterone's effects on the kidneys. Some cats show high blood pressure on routine screening, which may prompt further investigation. This page explores the signals that may suggest hyperaldosteronism, what is happening inside the body to produce those signals, how the condition is investigated through blood tests and imaging, and the approaches that exist for managing it over time. The goal is to help you understand the shape of the condition and the conversations that may follow.