Runny nose like water is usually due to allergic rhinitis and vasomotor rhinitis, acute rhinitis and so on. 1. Allergic rhinitis: it is generally common for allergic reactions to occur after contact between susceptible individuals and external allergens, manifesting as nasal itching, sneezing, running watery nose, nasal congestion, itchy eyes, etc. 2. Vasomotor rhinitis: generally due to neurotransmitter-mediated neurogenic inflammation of the nasal mucosa, manifested by nasal congestion, increased watery nasal discharge, and decreased sense of smell. 3. Acute rhinitis: viral infection leads to acute inflammatory reaction of the nasal mucosa and submucosa, which can be characterized by a runny nose like water. Runny nose like water is recommended to actively go to the hospital, systematic examination to clarify the cause of the disease .