Coughs are caused by an irritation in the lining of the throat or lungs, causing mucus build up. When you are sick, the lining of your throat and lungs becomes more sensitive. Cold air, eating or drinking, or sometimes just plain breathing can annoy the already tender lining. Coughs can tickle, or feel dry, making you clear your throat, or cough when you step into cold air. Some coughs are caused by mucus backing up in the throat or lungs. These coughs will end with the coughing up of mucus. These coughs can rattle, or bark. They can be spasmodic, as your body tries to eliminate the mucus. If you use cough drops, or cough syrups, you can prevent your coughs. This doesn’t fix the problem that caused the cough; it only suppresses the body`s natural desire to heal.