Why does my chest feel bruised when i cough?

Musculoskeletal pain: The chest wall has muscles, cartilage, bone, etc. When you cough, any of these structures can become painful; for example, you can develop muscle strain/sprain, cartilage can become inflamed, the bones can develop bone bruise or even fracture. The good news is that theses will heal once the cough resolves so see your doctor for diagnosis and treatment of the cough.