Acute PainPainPain ManagementPain MeasurementPain, PostoperativePain ClinicsPain ThresholdChronic PainAnalgesicsAnalgesics, OpioidAnalgesiaPain, IntractablePain PerceptionAnesthesia Department, HospitalFacial PainHyperalgesiaLow Back PainBack PainAcute DiseaseNeuralgiaAbdominal PainNeck PainAnalgesics, Non-NarcoticAnalgesia, Patient-ControlledPelvic PainUnited States Department of DefenseNociceptorsMorphinePain, ReferredRecovery RoomToothacheAcupunctureChronic DiseaseShoulder PainMusculoskeletal PainKetoprofenAnesthetics, LocalInjections, SpinalCyclohexanecarboxylic AcidsAnti-Inflammatory Agents, Non-SteroidalHot TemperatureDiclofenacCryingAnalgesia, EpiduralFormaldehydeNarcotic AntagonistsKetorolacKetamineAcetaminophenSkin Physiological PhenomenaTreatment OutcomeTranscutaneous Electric Nerve StimulationGanglia, SpinalAnesthesiologyLidocaineCapsaicinNociceptive PainBehavior, AnimalSpinal CordDexmedetomidineHerpes ZosterPeripheral Nervous System DiseasesAnesthetics, DissociativeDouble-Blind MethodBuprenorphineAnemia, Sickle CellCarrageenanInfant BehaviorQuestionnairesAminesNerve BlockPosterior Horn CellsCold TemperatureRats, Sprague-DawleyPhysical StimulationProspective StudiesNaloxoneTime FactorsMyofascial Pain SyndromesInflammationComplex Regional Pain SyndromesVisceral PainTRPV Cation ChannelsSeverity of Illness IndexDisease Models, AnimalDose-Response Relationship, DrugArthralgiaHydrocortisoneReceptors, Opioid, muEmergency Service, HospitalHong KongLabor PainWounds and Injuries