The common causes of sudden and continuous sneezing are as follows: 1. Protective behavior: It may be caused by the nasal mucosa suddenly coming into contact with air or polluting substances or particles, and the action of sneezing is a self-protective behavior that prevents polluting and irritating substances and particles from being inhaled into the lower respiratory tract. 2. Allergic rhinitis: Some patients may develop allergic rhinitis. This is mainly due to the contact of the nasal mucosa with dust, pollen and other allergenic substances, resulting in nasal allergy symptoms. 3, respiratory infections: Some patients may suffer from acute rhinitis or colds due to cold or respiratory viral infections, which also tend to cause Sudden continuous sneezing symptoms.