Every human will suffer from any degree of pain due to any kind of disease or injury, the most common types included headaches, colicky pain (caused by gastrointestinal inflammation), pressing pain (caused by coronary heart disease) and tearing pain (casused by joint sprains). The type of painkillers used to treat the different kinds of pain must be specific in order to relieve the pain effectively. There are two major categories of painkillers used to treat sport injuries such as muscle strains or joint sprains: The first category is Non-steroidal Anti-inflammatory Drugs (NSAID) which can be further divided into Non-selective COX Inhibitors and COX-2 Inhibitors. The former includes Panadol and Diclofenac, which are familiar to most people, whereas the latter includes the newly researched and developed Celecoxib and Etoricoxib. The drugs in this category suppress the Cyclooxygenase-2 (COX-2)activity and thereby reducing the post-trauma inflammation response, leading to the reduction of the feeling of pain. COX-2 Inhibitors even avoid the gastrointestinal side effects associated with the older NSAIDs. The second category is Muscle Relaxants such as Norflex which relieves pain by reducing muscle spasms. When athletes suffer sports accidents which cause injuries to bones, muscles, soft tissues and joints, doctors will typically prescribe anti-inflammatory painkillers for treatment. However, some patients often misunderstand that painkillers does not help to improve the condition of illness, they are only meant to relieve pain and will conceal the condition of the illness. Moreover, they may also be overly concerned with the side-effects of the painkillers and not taking them regularly, or not taking any painkiller at all. In fact, the most important function of anti-inflammatory painkillers is to reduce and suppress the reaction of inflammation. When the inflammation reaction  is reduced or ceased, the pain caused by inflammation mediators and edema will also be relieved. During the treatment process, the doctor will also prescribe other drugs or treatments in addition to anti-inflammatory painkillers to treat the disease or injury and to prevent the side effects of painkillers so that it allows the injury to heal as quickly as possible.