Sneezing includes the defensive reflex made by the body after the respiratory tract is stimulated by a foreign body, allergic reaction and inflammatory stimulation caused by other conditions. 1. Foreign body stimulation: In daily life, some foreign body or dust enters into the nose, the nasal mucous membrane is stimulated by the foreign body, there will be sneezing as a reflex, just one or two, this situation does not need to be dealt with. 2. Allergic rhinitis, when we are stimulated by pollen, we will sneeze continuously, some people may sneeze dozens of times a day, along with sneezing, there will also be a runny nose, the nose will be particularly itchy, and there will be symptoms of nasal congestion. 3. Acute rhinitis: generally caused by viral infections, there will be sneezing symptoms, but the number of times is not as much as allergic rhinitis, the early stage of the cold will have a clear runny nose, there will be fever, generalized weakness of the symptoms. There are more causes of sneezing, such as persistent or frequent recurrent sneezing, it is recommended to actively consult a doctor for systematic examination to clarify the diagnosis and causes.