Frequent sneezing is related to a number of factors.
Firstly, it may be related to an infectious disease. When the nasal or throat tissues become infected, the mucous membrane of the nose or throat is stimulated by inflammation, leading to mucosal congestion and continuous leakage of secretions, and the body reacts physiologically by sneezing in order to be able to expel the secretions.
Secondly, it may be related to allergic factors such as dust, pollen, air pollutants, etc. When the tissue lining the nose or throat is stimulated by contact with allergens, the body reacts defensively out of a protective mechanism, causing the sneezing phenomenon to occur.