I have chest congestion that i can feel up to my neck. when i cough, i get a very sharp pain. what could be the cause of this?

There are many...: There are many potential causes of pain with coughing; some of them are mild (ie. Bronchitis, viral infections, etc.) and some are more serious (ie. Clots in the lungs). The cause would have to be worked up thoroughly by a physician, after a complete history and physical examination, to rule out some of the more serious potential causes.

Possibilities...: If it has been present for less than 3 weeks, it is likely acute bronchitis which is usually of viral or bacterial origin. It will likely resolve on its own in a few days to week. If present for 3 weeks or more, it could be chronic bronchitis, a form of copd. This would need a doctor evaluation so treatment could be given.