Recently, sneezing may be caused by common cold or allergic rhinitis. 1. Common cold is caused by viral infection, also known as “acute rhinitis”, the main manifestation is nasal symptoms, such as sneezing, runny nose, and later on, nasal congestion. Generally, it can be cured in 5-7 days, or it can be improved without treatment. 2. Allergic rhinitis has sudden and continuous sneezing, itchy nose, nasal congestion, and a lot of nasal discharge. Most of them are caused by allergens, and the symptoms can be relieved within minutes to hours if they are removed from the allergens. In addition, coughing and sneezing can occur when fungal hyphae or other substances are inhaled in a humid environment. Whichever of the above is the case, the symptoms of constant sneezing need to be addressed after the cause has been identified.