It is a chronic inflammatory disease that attack or take place in the respiratory airways, it is a common disease characterized by mutable and periodic symptoms, reversible airflow obstruction, and bronchospasm. The main factors that play significant role in the incidence of asthma are either genetic factor or environmental factor or others. In case of environmental factor it will includes various sub-factors which play role in incidence of asthma attack like allergy ( allergy to: dust, animal fur, cockroaches, mold, and pollens from trees, grasses, and flowers), air pollution, cigarettes, environmental chemicals, spray i.e., like hair spray, and different environmental chemicals. While for genetic factor, it has been found that more than 100 genes associated with asthma, besides that these genes are related with the immune system or modulating inflammation that happened. Moreover, clinically it has been found that some of these genes will play a significant role in causing asthma only when combined with specific environmental conditions.