Patient respiration may be characterized using a marked respiration waveform involving a respiration waveform annotated with symbols, markers or other indicators representing one or more respiration characteristics. A respiration waveform may be acquired by sensing a physiological parameter modulated by respiration. A marked respiration waveform may be generated based on the acquired respiration waveform and one or more detected respiration waveform characteristics and/or respiration-related conditions. One or more components used to generate the marked respiratory waveform may be fully or partially implantable.