The causes of allergic rhinitis are divided into the following categories: 1. Inhalation allergens, which are very common in life, including those related to the seasons, are pollen. For example, pollen is the most common in northern China, and willow wadding in spring is the most common, followed by dust mites, animal fur, etc. can cause allergic reactions. Called inhalation allergens; 2, may have some relationship with environmental factors. Such as now with the increase in atmospheric pollution, car exhaust emissions, may cause an increase in the proportion of patients with allergic diseases. According to the existing research, the cause of allergic rhinitis may be related to environmental, genetic and inhalant allergens. It is now possible to perform serological tests or local excitation tests for inhalant allergens to determine which substance one is allergic to.