Running water in the nose may be caused by allergic rhinitis, or it may be caused by ruptured sinus cysts and cerebrospinal fluid nasal leakage. 1. Allergic rhinitis: contact with allergenic drugs, pollen, etc., causing the parasympathetic nerves to become more active and the glands to hypersecrete, resulting in an increase in nasal discharge, nasal congestion, sneezing, and running water in the nose. 2. Rupture of sinus cysts: Sinus cysts grow to a certain extent and rupture, and the affected side of the nasal cavity repeatedly flows yellowish watery fluid. 3. Cerebrospinal fluid leakage: Cerebrospinal fluid leakage is common after trauma or surgery, causing nasal water, like watery nasal mucus. There are other factors in the nose, should be timely to the regular hospital otolaryngology outpatient clinic, under the guidance of the doctor for treatment, do not self-diagnosis and medication, in order to avoid delaying the condition, resulting in serious adverse consequences.