I Have A Cough And When I Cough Mucus Expels

I have a cough and when I cough mucus expels from my mouth it is not a thick mucus and it has no color I have a nasal drip it has no color it is also clear after a coughing spell my diaphragm is left sore and I am exhausted from the coughing spell it happen through out the day but is worst when I try to lye down to sleep