Thomas Addison identified this disease in 1855. Addison’s disease is adrenal cortical insufficiency due to the destruction or dysfunction of the adrenal cortex. It affects glucocorticoid and mineralocorticoid function. 90% of the adrenal cortices are damaged before the disease shows up. The condition affects those ages 30-50 years. The clinical features of Addison’s include progressive weakness, fatigue, poor appetite, and weight loss.