Sodium chloride at 0.9%, i.e. saline, is often used to wash the nose without adding water. Sodium chloride solution is a sterile solution, commonly used at a concentration of 0.9%, also known as saline, which can be used to treat sinusitis, rhinitis and other diseases by washing the nose. Saline can also be applied to excessive secretions or dirt in the nose without irritating the mucous membranes of the nasal cavity, and does not need to be filled with water. High concentration of sodium chloride can cause nose damage, so the doctor will clearly prompt the application of 0.9% sodium chloride, i.e. saline. To clean the nasal cavity, it is recommended to rinse with saline and use it as prescribed by the doctor to avoid affecting the efficacy or causing damage.