Hello, Thank you for your query. *did they do a chest Xray? Did they examine your throat and lungs? *do you have chest pain or breathing difficulty? *are you as asthmatic? Or have and allergy issues like Wheezing.? *do you cough while eating or drinking or laying down? *is the cough productive or dry? *what sort of accident? Any oil spills or fire/smoke? *did you get any other injury? It could be a Reactive airway disease (due to exposure to fumes or smoke) with inflammation and secretions. If there was any chest impact minor internal bleeding can irritate the airway and cause cough. I suggest you talk to your doctor about this symptom to see of it should be related to the accident. In the mean time, do steam inhalations and have warm water with honey to soothe your throat Please visit the ER if you have Breathing difficulty or cough up blood. Hope this helps. Please let me know if there is anything else I can help you with. Wish you good health