What Causes a Runny Nose with Clear Discharge?

What causes a runny nose with clear, watery discharge? The most common cause is rhinorrhea—typically associated with rhinitis, especially allergic rhinitis. In such cases, the clear nasal discharge is often accompanied by sneezing, nasal itching, and other symptoms. If you experience clear nasal discharge along with sneezing and nasal itching, it is highly likely that you are experiencing an episode of allergic rhinitis.

First, avoid exposure to known allergens. Then, consider pharmacological treatment—including antihistamines and intranasal corticosteroid sprays.

Second, clear, watery nasal discharge may also occur following trauma—or occasionally in children—necessitating prompt medical evaluation to rule out cerebrospinal fluid (CSF) rhinorrhea. Particularly after head trauma, unilateral clear nasal discharge warrants immediate hospital assessment to exclude CSF leakage.

If CSF rhinorrhea is confirmed, timely hospital referral is essential, as surgical repair is often required. Prolonged untreated CSF rhinorrhea significantly increases the risk of intracranial infection. Therefore, we emphasize: any clear nasal discharge or watery nasal leakage following trauma must be taken seriously and promptly evaluated at a hospital to rule out CSF rhinorrhea.