Pain is accepted as the fifth vital sign in many contries, after pulse, respiration, temperature and blood preasurre. It plays an important role in making us aware that something wrong is going on in our bodies and we need to take care of it. Basic knowledge about the pathways of pain, modulation of pain and the pathophysiology of chronic and presistent pain, modulation of pain and the pathophysiology of chronic and presistent pain is very important in undergraduating different kinds of pain in a better way. This book provides everything students need to know about pain management.