Nasal breathing apparatuses for delivering gases, monitoring end-tidal CO2, and providing CPAP and NIV through a patient's nose are provided, including a central tubular chamber, a pair of nasal sealing members, one or a pair of breathing tube(s), an inner central tube, one or a pair of delivery tube(s), and a pair of side straps coupled with a head strap. Inner central tube and delivery tube(s) are positioned inside central tubular chamber and breathing tube(s), respectively. Alternatively, central tubular chamber and breathing tube(s) have a double lumen configuration. The nasal breathing apparatuses are compact and lightweight and have reduced noise during use.