Exposure to factors like pollution, allergen, dust mites, dander, high ozone levels, viral infection, cold, influenza(flu), exercise, running, chemicals, traffic pollution, etc., make asthmatic symptoms worse. Indoor triggering factors may include dust, dirt, unhygienic factors such as animal dander, dusty and untidy living spaces. High exposure to the factors mentioned above may lead to deadly uncontrollable asthmatic attacks.