Methods and systems are provided that determine whether a patient is breathing irregularly. A system may receive a physiological signal, such as a plethysmographic signal or an end-tidal carbon dioxide signal, from a sensor. The system may analyze the signal for one or more features indicative of irregular breathing, which may be a result of a patient talking, moving, yawning, coughing, sneezing, or the like. The system may also be configured to provide an indication of the irregular breathing.
