Described herein are nasal respiratory devices and methods for treating a variety of medical diseases including snoring and sleep apnea through the use of such devices. In general, these devices include an airflow resistor, such as a flap valve and a holdfast for securing the device in communication with the subject's nasal cavity. The devices may be configured to include leak paths to regulate the expiratory pressure when worn by a subject. Methods for using these devices may include securing a device over or at least partially within (or both of) a subject's nasal cavities.