Abstract: Improved passive resistance nasal devices for treating a patient (and particularly, but not exclusively, a sleeping patient) that inhibit exhalation more than inhalation. For example, described herein are passive-resistance nasal devices having a variable sized opening leak path that change the size of the leak path opening depending on the pressure extended across the nasal device. Also described herein are passive nasal devices including a deployable insertion guide member. Also described herein are passive nasal devices including an extension member to hold the airflow resistor portion of the nasal device slightly apart from the subject's nose, even as the nasal device itself may be secured against the nose or nostril openings. Methods of operating these nasal devices and methods of treating patients using these devices are also described.