Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Left untreated, leprosy can be progressive, causing permanent damage to the skin, nerves, limbs and eyes. Contrary to folklore, leprosy does not cause body parts to fall off, although they can become numb or diseased as a result of secondary infections. Learn more about leprosy, its causes, symptoms and treatment in the following pages.