Cardiovascular Physiological PhenomenaDental Physiological PhenomenaDigestive System and Oral Physiological PhenomenaReproductive and Urinary Physiological PhenomenaMusculoskeletal and Neural Physiological PhenomenaPulmonary Disease, Chronic ObstructiveCirculatory and Respiratory Physiological PhenomenaIntegumentary System Physiological PhenomenaSports Nutritional Physiological PhenomenaReproductive Physiological PhenomenaPhysiological PhenomenaElder Nutritional Physiological PhenomenaUrinary Tract Physiological PhenomenaMusculoskeletal Physiological PhenomenaLung Diseases, ObstructiveVirus Physiological PhenomenaForced Expiratory VolumeDigestive System Physiological PhenomenaSpirometryRespiratory Function TestsBronchodilator AgentsBlood Physiological PhenomenaLung DiseasesDyspneaVital CapacityLungAdolescent Nutritional Physiological PhenomenaOcular Physiological PhenomenaPulmonary EmphysemaRespiratory Physiological PhenomenaScopolamine DerivativesNervous System Physiological PhenomenaSmokingAdministration, InhalationCell Physiological PhenomenaSkin Physiological PhenomenaPrenatal Nutritional Physiological PhenomenaOxygen Inhalation TherapyPlant Physiological PhenomenaSputumSeverity of Illness IndexBacterial Physiological PhenomenaExercise ToleranceEmphysemaCholinergic AntagonistsMaternal Nutritional Physiological PhenomenaRespiratory MusclesRespiratory System AgentsIpratropiumAlbuterolAsthmaChild Nutritional Physiological PhenomenaSmokeBronchiAdrenal Cortex HormonesRespiratory InsufficiencyBronchitis, ChronicNutritional Physiological PhenomenaAdrenergic beta-2 Receptor AgonistsTreatment OutcomeQuality of LifeInfant Nutritional Physiological PhenomenaPulmonary MedicineTime FactorsInspiratory CapacityRisk FactorsCase-Control StudiesPneumoniaExpectorantsRespiratory Mucosaalpha 1-Antitrypsin DeficiencyRespiratory TherapyNebulizers and VaporizersBronchoalveolar Lavage FluidBronchitisProspective StudiesInhalationOxygenHospitalizationBlood Gas AnalysisChronic DiseaseBronchiectasisExercise TestRetrospective StudiesBreathing ExercisesRespiration, ArtificialDisease ProgressionPositive-Pressure RespirationHypercapniaRespiratory MechanicsWork of BreathingQuestionnairesBronchoscopyHeliumComorbidityRaynaud DiseaseExhalationRespiratory SystemNoninvasive VentilationLung Volume Measurements