Conn's syndrome is characterized by an excess of which hormone?

Conn's syndrome, also known as primary hyperaldosteronism, is characterized by an excess of aldosterone, which is a hormone produced by the adrenal glands. Aldosterone plays a crucial role in regulating blood pressure by controlling the balance of sodium and potassium in the blood. When there is an excess of aldosterone due to Conn's syndrome, it leads to increased sodium reabsorption, resulting in elevated blood volume and, consequently, hypertension. The condition can also lead to hypokalemia (low potassium levels) due to the increased excretion of potassium by the kidneys.

Understanding the role of aldosterone in sodium and potassium homeostasis is essential in the context of this syndrome. The other hormones listed are not the focus in Conn's syndrome; cortisol is associated with Cushing’s syndrome, insulin is involved in glucose metabolism, and thyroxine regulates metabolism, none of which pertain to the specific cause and effects of Conn's syndrome.