Cushing's syndrome

The presence of excess cortisol in the body is called hypercortisolism, or Cushing's syndrome, after Dr. Harvey Cushing who first described the condition in 1932. The pathology can arise from exogenous administration of cortisol or from hormone secreting tumors present at either the adrenal cortex (primary hypersecretion) or anterior pituitary (secondary hypersecretion). If the pituitary autonomously secretes ACTH the condition is known as Cushing's disease. (Hypercortisolism due to any cause is called Cushing's syndrome).

The majority of the signs of hypercortisolism can be predicted from the normal range of actions of cortisol. The hormone cortisol is essential for life and serves several purposes in the human body. It's main function is to maintain blood glucose levels, which it does throuh a variety of mechanisms. Cortisol promotes gluconeogenesis (glucose production) in the liver, causes the breakdown of skeletal muscle proteins to provide amino acids for gluconeogenesis, suppresses the immune system by preventing antibody production by white blood cells, causes a negative calcium balance in the body, and influences brain function by causing mood swings and changes in memory and learning abilities. In patients with Cushing's syndrome, diabetes is mimicked due to excess gluconeogenesis and tissue wasting occurs as muscle protein is broken down for glucose production. Interestingly, however, extra fat is deposited in the trunk and face of patients due to increased appetite, causing the appearance of a plump "moon face." Extremeties are usually thin, learning and memory become difficult, and an initial mood elevation is followed by depression.