**2. Pain**

Why god created pain? To the author, the answer to this question explains the term "productive pain" which has been described in literatures as a warning on the occurring of injury in the body. This pain will guide the person to seek treatment, and this pain will also facilitate diagnosis. "Nonproductive" pain by definition serves no purpose either as a warning or diagnostic tool. It is important for us to understand pain pathophysiology for management purpose.

Pain syndromes may be different, but their sensory pathways are the same. It starts from the affected organ and the message flow to the brain for interpretation. The pharmacological path of analgesics' action is by working at the level of the nerves, they work by either blocking the signal originating from the peripheral nervous system, or can work centrally by distorting the interpretation by the central nervous system.

Practitioners' selection of an appropriate analgesic is first based on the type of pain and severity and then the knowledge of risk and extra benefit and indirectly considering existing risk‐benefit of a particular drug. The decision will also depend on the knowledge on the classes of drugs, and their adverse effect. Text books have divided pain into two classes, acute and chronic. In selecting the analgesic to be used, severity and predicted survival of patient must also be considered as a selection criteria [2].

## **2.1. Acute pain**

Acute pain duration is self‐limiting and this includes postoperative pain, pain of injury, and childbirth. This type of pain is foreseen to be short in duration so the treatment using narcotic pain killer is considered to be safe as there will not be long‐term addiction prob‐ lem on using narcotics. Using NSAIDs will also be beneficial as it allows fluctuation of dose but with limiting concern on the risk of ulcers. For both categories of painkillers, their doses may be adjusted based on observation of healing rate, changing doses from high to low doses, and from narcotic analgesics to nonnarcotics as required. In severe pain, it is the rule of thumb that patients should not be subject to the return of pain so painkiller needs to be dosed adequately to ensure that pain is at least tolerable to avoid the occurrence of anxiety, usually after the return of pain [3]. Generally, in pain management, painkiller should never be dosed on as needed basis, but should be administered often enough to assure effective plasma level (this could be warrantied with the use of a sustained release preparation).
