A system for non-invasively detecting and monitoring medical conditions using multiple modalities of sensing, comprising: a device comprising: atleast two electrodes (114a-d) configured to be positioned on a subject; an acoustic sensor configured to be positioned on a subject; a sensor configured to measure an orientation of the device; a thoracic impedance measurement module connected to the atleast two electrodes (114a-d), configured to measure a first impedance between the at least two electrodes when the device is in a first orientation, wherein the first orientation indicates that the device is approximately horizontal, and a second impedance between the at least two electrodes when the device is in a second orientation, wherein the second orientation indicates that the device is at an angle with respect to a horizontal plane; and a heart acoustic measurement module connected to the acoustic sensor, configured to detect and measure a heart sound from the acoustic sensor, wherein the device is configured to gather multi-modality sensing data, and wherein the multi-modality sensing data includes the first and second impedances and the heart sounds; and a data analyzer operative to perform at least one of data analysis, data trending, and data reduction of the multi-modality sensing data, characterized in that the data analyzer is configured to analyze the first and second impedances to determine a change in impedance, and wherein the change in impedance indicates a presence or absence of fluid in lungs of the subject a device comprising: atleast two electrodes (114a-d) configured to be positioned on a subject; an acoustic sensor configured to be positioned on a subject; a sensor configured to measure an orientation of the device; a thoracic impedance measurement module connected to the atleast two electrodes (114a-d), configured to measure a first impedance between the at least two electrodes when the device is in a first orientation, wherein the first orientation indicates that the device is approximately horizontal, and a second impedance between the at least two electrodes when the device is in a second orientation, wherein the second orientation indicates that the device is at an angle with respect to a horizontal plane; and a heart acoustic measurement module connected to the acoustic sensor, configured to detect and measure a heart sound from the acoustic sensor, wherein the device is configured to gather multi-modality sensing data, and atleast two electrodes (114a-d) configured to be positioned on a subject; an acoustic sensor configured to be positioned on a subject; a sensor configured to measure an orientation of the device; a thoracic impedance measurement module connected to the atleast two electrodes (114a-d), configured to measure a first impedance between the at least two electrodes when the device is in a first orientation, wherein the first orientation indicates that the device is approximately horizontal, and a second impedance between the at least two electrodes when the device is in a second orientation, wherein the second orientation indicates that the device is at an angle with respect to a horizontal plane; and a heart acoustic measurement module connected to the acoustic sensor, configured to detect and measure a heart sound from the acoustic sensor, wherein the device is configured to gather multi-modality sensing data, and wherein the multi-modality sensing data includes the first and second impedances and the heart sounds; and a data analyzer operative to perform at least one of data analysis, data trending, and data reduction of the multi-modality sensing data, characterized in that the data analyzer is configured to analyze the first and second impedances to determine a change in impedance, and wherein the change in impedance indicates a presence or absence of fluid in lungs of the subject