Patients with symptoms of clear water running from one side of the nose are commonly caused by the following reasons: 1. Acute rhinitis: It may be caused by the recent cold, or suffer from respiratory viral infection, causing acute rhinitis, which is usually called cold, and may lead to the symptoms of clear water running from one side of the nose. 2. Allergic rhinitis: It is mainly due to the contact of nasal mucosa with dust, pollen, willow and other allergens, Allergic nasal symptoms caused by allergenic substances such as dust, pollen, willow, etc., tend to occur more easily in the spring and autumn when allergies are prevalent. Patients often suffer from nasal congestion, nasal itching, sneezing and other related symptoms to varying degrees. If too much clear nasal snot accumulates in the nasal passages, the nasal cavity can also be properly cleared to help maintain a good state of nasal and sinus patency and drainage.