Water running inside the nose may be related to allergic rhinitis, vasomotor rhinitis and maxillary sinus cysts and other factors. 1. Allergic rhinitis: allergic rhinitis is often triggered by a combination of genetic factors and inhalation of allergens, etc. If an allergic reaction occurs in the nasal cavity, histamine and other allergic factors stimulate the mucous membrane of the nasal cavity to increase secretion, and a watery secretion may flow out of the nose. 2. Vasomotor rhinitis: vasomotor rhinitis is caused by autonomic dysfunction, when the parasympathetic nervous excitability increases, it can promote the release of acetylcholine, which in turn causes an increase in nasal mucous membrane secretion, that is, water flowing from the nose. 3. Maxillary sinus cysts: Maxillary sinus cysts are usually caused by the blockage of maxillary sinus mucosal glandular ducts, resulting in the accumulation of mucus in the sinus mucosa and the formation. When a maxillary sinus cyst ruptures on its own, it can cause fluid to accumulate in the nasal cavity, and the yellow fluid will flow out of the nose. If you have water coming out of your nose, you should go to a regular hospital to find out the cause of the problem and choose the right treatment for yourself under the guidance of a professional doctor.