Alternating nasal congestion is generally common in the following diseases: 1. Chronic rhinitis. Chronic rhinitis is a symptom associated with acute rhinitis that does not heal and is caused by repeated inflammatory stimulation. Patients will have unilateral nasal congestion with alternating changes. Often, the downward nostril is not ventilated and the upward nostril is ventilated. In this case, the patient needs to apply topical Daphnelean spray and exercise to restore the contraction and diastolic function of the turbinates. The nasal cavity needs to be rinsed repeatedly with saline, and it can be gradually cured in about a month. 2. Allergic rhinitis, a nasal symptom caused by the inhalation of allergens in the nose. Patients will have bilateral nasal congestion with alternating changes, morning sneezing and clear water-like nasal discharge. Allergic rhinitis requires oral anti-allergy medication such as Cisplatin or Loratadine, as well as topical topical application of Cozultan or Endosulfan to the nasal passages. It will gradually heal in about a week.