Pain is the unpleasant sensation that we experience in association with actual or potential tissue damage, while nociception is the neural process of encoding a noxious stimulus. Suffering and disability resulting from pain lead to decrease quality of life for many people. Many of the researchers, physiologic mechanisms in response to pain, anatomical pathways and neurotransmitters were studied. Neurotransmitters such as 5-hydroxy-tryptamine, Bradykinin, Histamine, Eicosanoids, the leukotrienes and hydroxy acid and cytokinins are associated with pain. Therefore pain control or pain relief is one of the important targets in the treatment of diseases and It is important for clinicians, Despite the pathological point is not curable. Qualified medical personnel using medication for pain reduction. These drugs are divided into five groups: Opioid drugs, Steroids, Non-steroidal anti-inflammatory drugs(NSAIDs), Topical anesthetics and General anesthetics. Sometimes, traditional methods other drugs and traditional methods are used to reduce pain. The pathophysiology of pain and effective drugs in its control and integration of information and Optimization, It is necessary.