A system to monitor a characteristic of a lung, the system comprising: a pressure generator configured to generate a pressurized flow of breathable gas for delivery to the airway of a subject; one or more sensors configured to generate one or more output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas; a control module configured to control the pressure generator to adjust one or more levels of the one or more gas parameters of the pressurized flow of breathable gas, a perturbation module configured to determine one or more perturbation parameters defining perturbations to be applied to the levels of the one or more gas parameters of the pressurized flow of breathable gas, wherein the control module is configured to control the pressure generator such that the levels of the one or more gas parameters of the pressurized flow of breathable gas include the perturbations defined by the perturbation module; and one or more processors configured to execute computer program modules, the computer program modules comprising: a parameter determination module configured to determine a respiratory parameter, wherein the parameter determination module is further configured to determine a monitoring parameter that reflects a change between a first measurement of the respiratory parameter and a second measurement of the respiratory parameter, and a detection module configured to detect, monitor, and/or quantify a characteristic of a lung of the subject based on the monitoring parameter, characterized in that the first measurement is taken before a sleep session, and the second measurement is taken subsequent to the sleep session to allow for an observed change in the respiratory parameter between the first measurement and the second measurement, wherein the perturbation module is configured to gradually sweep through frequencies of perturbations to be applied such that one of the perturbation parameters includes a range of frequencies of perturbations to be applied. a pressure generator configured to generate a pressurized flow of breathable gas for delivery to the airway of a subject; one or more sensors configured to generate one or more output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas; a control module configured to control the pressure generator to adjust one or more levels of the one or more gas parameters of the pressurized flow of breathable gas, a perturbation module configured to determine one or more perturbation parameters defining perturbations to be applied to the levels of the one or more gas parameters of the pressurized flow of breathable gas, wherein the control module is configured to control the pressure generator such that the levels of the one or more gas parameters of the pressurized flow of breathable gas include the perturbations defined by the perturbation module; and one or more processors configured to execute computer program modules, the computer program modules comprising: a parameter determination module configured to determine a respiratory parameter, wherein the parameter determination module is further configured to determine a monitoring parameter that reflects a change between a first measurement of the respiratory parameter and a second measurement of the respiratory parameter, and a detection module configured to detect, monitor, and/or quantify a characteristic of a lung of the subject based on the monitoring parameter, characterized in that the first measurement is taken before a sleep session, and the second measurement is taken subsequent to the sleep session to allow for an observed change in the respiratory parameter between the first measurement and the second measurement, wherein the perturbation module is configured to gradually sweep through frequencies of perturbations to be applied such that one of the perturbation parameters includes a range of frequencies of perturbations to be applied.