Rhinorrhea

Rhinorrhea, commonly known as a runny nose, consists of an unusually significant amount of nasal discharge. It is a symptom of the common cold and of allergies (hay fever).

The term comes from the Greek words "rhinos" meaning "of the nose" and "rhoia" meaning "a flowing." Rhinorrhea can also be a sign of withdrawal, such as from opioids (especially methadone).

Rhinorrhea may be due to allergic conditions such as hay fever or foreign materials within the nostril. Bacterial or viral infections such as the common cold, influenza or sinusitis may also be accompanied by a runny nose. Nasal discharges may also be present in cases of vasomotor rhinitis, a non-infectious and non-allergenic condition.

Head injuries may also cause excess nasal discharges. Basilar skull fracture may result in cerebrospinal fluid rhinorrhea.

Environmental causes include contact with strong smelling substances such as disulfide compounds found in onions and garlic, both of the genus Allium. CS gas, which provides an especially intense pepper-like odor, also results in this symptom. This phenomenon is caused by the same mechanism that causes a runny nose when crying: tears drain through the inner corner of the eyelids through the nasolacrimal duct, and finally into the nasal cavity, where they manifest as a runny nose.


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