Pain ThresholdPainPain MeasurementPain ManagementPain PerceptionEar, ExternalHot TemperatureDiffuse Noxious Inhibitory ControlHyperalgesiaAnalgesiaAnalgesics, OpioidAnalgesicsAnalgesics, Non-NarcoticCold TemperaturePressureAlfentanilWristTranscutaneous Electric Nerve StimulationPentazocinePhysical StimulationFibromyalgiaChronic PainSensory ThresholdsElectric Stimulation TherapyCatechol O-MethyltransferasePain, PostoperativeDouble-Blind MethodBack PainLow Back PainCross-Over StudiesAbdominal PainSex CharacteristicsMorphineNeck PainPain, IntractableCapsaicinElectric StimulationPelvic PainFacial PainAcute PainPain, ReferredSkinTime FactorsCost of IllnessSeverity of Illness IndexShoulder PainMusculoskeletal PainCritical IllnessChronic DiseaseModels, BiologicalNociceptive PainNeuralgiaIllness BehaviorMental DisordersQuestionnairesTreatment OutcomeMyofascial Pain SyndromesComplex Regional Pain SyndromesVisceral PainProspective StudiesArthralgiaLabor PainQuality of LifeAcute DiseaseUnited StatesSick RoleDisability EvaluationAdaptation, PsychologicalRisk FactorsNociceptorsFollow-Up StudiesCross-Sectional StudiesRetrospective StudiesPrevalenceFeverInfluenza, HumanAnesthetics, LocalAttitude to HealthFoodborne DiseasesCatastrophizationComorbidityRespiratory Tract InfectionsFlank PainMentally Ill PersonsCohort StudiesEye PainGastrointestinal DiseasesDepressionInfant, NewbornStereotypingStress, PsychologicalAge FactorsPsychotic DisordersHealth StatusActivities of Daily LivingBipolar DisorderPopulation SurveillanceRespiratory Tract DiseasesAnalysis of VarianceMusculoskeletal Diseases