Measures of Respiratory Health Registry

Participants with CF Inclusion Criteria: -Diagnosis of CF as evidenced by one or more clinical feature consistent with the CF phenotype or positive CF newborn screen AND one or more of the following criteria: i. A documented sweat chloride ≥ 60 mEq/L by quantitative pilocarpine iontophoresis (QPIT). ii. A documented genotype with two disease-causing mutations in the CFTR gene. \- In the opinion of the investigator, the participant will likely have the ability to perform the lung function test of interest on the day of testing Exclusion Criteria: * Physical findings at the screening that would compromise the safety of the participant or the quality of the data (e.g. respiratory distress or work of breathing) * Requirement of supplementary oxygen to maintain oxygen saturation above 95% Participants with other Respiratory Disease Inclusion criteria: * Physician-diagnosed lung disease * Informed consent by participant, parent, or legal guardian * In the opinion of the investigator, the participant will likely have the ability to perform the lung function test of interest on the day of testing Exclusion criteria * Physical findings at screening that would compromise the safety of the participant or the quality of the research data * Requirement of supplementary oxygen to maintain oxygen saturation above 95% Healthy Participants * Inclusion criteria * Informed consent by participant, parent, or legal guardian * In the opinion of the investigator, the participant will likely have the ability to perform the lung function test of interest on the day of testing Exclusion criteria * Physical findings at screening that would compromise the safety of the participant or the quality of the research data * Evidence of lung disease