Fresh water can lead to edema of the nasal mucosa, where the intracellular structures cause membrane rupture and cell death due to edema. The nasal mucosa can become dry and crusty, even oozing blood, blood in the snot and painful discomfort. What to know about nasal irrigation Nasal irrigation, which has been used for a century to treat nasal and sinus disorders, is an inexpensive and effective treatment for nasal disorders, and this treatment has great potential. Because of its good efficacy and tolerance, nasal irrigation has been welcomed by doctors and patients, especially in recent years, with the popularization of sinus endoscopy, sinus endoscopic surgery has become a routine surgery in ENT, and after sinus endoscopic surgery, how to promote the early recovery of the mucosa of the operative cavity and prevent the adhesion of the operative cavity and the closure of the sinus opening is a clinical problem that needs to be solved urgently, and nasal irrigation is an Therefore, in-depth research on nasal irrigation has been conducted at home and abroad, and this paper attempts to introduce the latest research progress. 1.Indications for nasal irrigation Nasal irrigation as a treatment method is widely used in the treatment of various diseases of the nasal cavity and sinuses. Nasal irrigation can be applied to different conditions, including acute and chronic rhinosinusitis, allergic and non-allergic rhinitis, non-specific nasal symptoms (such as post-nasal runny nose), nasal septal perforation, post-operative nasal surgery, and post-nasal radiotherapy. It can also be applied to common cold. 2. In some cases it is also able to reduce medication. It is not just an adjunctive treatment, but an important part of the treatment process, which is effective and has not been fully utilized. 3, For the nasal sinus and other postoperative applications of nasal rinses can significantly reduce the patient’s mucosal edema, scab formation and other adverse reactions, and reduce the number of times patients seek help from doctors. 4. Garavello W et al. studied the effect of hypertonic saline nasal irrigation on seasonal allergic rhinitis and found that hypertonic saline nasal irrigation could significantly improve patients’ symptoms and reduce the use of oral antihistamines. Therefore, he recommended hypertonic saline nasal rinses for patients with seasonal allergic rhinitis during pollen season. 5, Klossek JM has achieved good results in patients with nasal polyposis treated with postoperative nasal irrigation and topical steroid hormone therapy after conventional sinus endoscopic surgery, so he believes that postoperative nasal irrigation and topical steroid hormone nasal spray can consolidate the efficacy of endoscopic surgery. Recently, the European Academy of Allergy and Clinical Immunology (EAACI) and the European Rhinology Society guidelines on sinusitis and nasal polyps include nasal irrigation as an important treatment measure for sinusitis and nasal polyps. The mechanism of action of nasal irrigation is a simple, economical and effective treatment that can significantly relieve the symptoms of the patient’s nasal cavity and sinuses and reduce bacterial resistance due to the reduction in the amount of drug therapy. However, the exact action and mechanism of nasal irrigation is not well understood now, and most people believe that it may be related to the following mechanisms, improving mucosal cilia function; decreasing mucosal edema; and reducing inflammatory factors. Physical or mechanical clearance The mucus layer of the nasal cavity is the first line of defense of the organism and contains a lysis layer and a gel layer, where foreign bacteria, fungi, and allergens can be captured by the mucus layer. The oscillation of the cilia is mainly controlled by the gel layer, and the oscillation of the cilia towards the nasopharynx allows foreign bodies to be swallowed or spit out in the nasopharynx. Therefore, the functional state of cilia is closely related to the functional state of the nasal cavity.3 Therefore, a lot of research has been done on the effect of nasal rinsing on cilia, and the effect of different nasal rinsing solutions on mucosal cilia has been studied from different perspectives.