The nasal cannula (NC) is a device used to deliver supplemental oxygen or increased airflow to a patient or person in need of respiratory help.

This device consists of a lightweight tube which on one end splits into two prongs which are placed in the nostrils curving toward the sinuses behind the nose, and from which a mixture of air and oxygen flows.

The earliest, and most widely used form of adult nasal cannula carries 1–3 litres of oxygen per minute.

Rates above 5 L/min can result in discomfort to the patient, drying of the nasal passages, and possibly nose bleeds (epistaxis).

[9] Definition: Non-invasive delivery of oxygen air mixture delivered via a nasal cannula at flows that exceed the patient's inspiratory flow demands with gas that has been optimally conditioned by warming and humidifying the gas to close to 100% relative humidity at body temperature.