Like the first edition, the second edition of the Encyclopedia of Stress covers nearly every conceivable aspect and ramification of stress including a wide range of related topics such as neuroimmune interactions, cytokines, enzymatic disorders, effects on the cardiovascular system, immunity and inflammation, and physical illnesses. Over the last decade, scientists have presented convincing research showing that psychological stress increases vulnerability to disease. They now understand more clearly that stress may be the thread tying together illnesses that were previously believed to be unrelated. Bone loss, increased abdominal fat, and damaged memory cells in the hippocampus have been linked to elevated cortisol levels.