Diseases have a history, and understanding that history helps us understand how best to treat and control disease today. Today's students are confronted with a panoply of often-frightening illnesses and afflictions - the series provides students with the information that they need to understand the origin of various maladies, how they impact contemporary society, and how doctors and researchers from around the world are fighting to devise treatments to alleviate or cure these diseases. This volume, , covers a disease that has been a common affliction from the beginning of recorded history, but has been increasing in its impact because of changes in diet and exercise, especially among the young.