Hi Barge1003,
There is really not enough information to go by. But sharp back pain with coughing may sometimes indicate a lumbar disc related problem or sciatica. Although you did not mention any pain going down you leg which is usually a feature of sciatica-type back pain.
I have recently written an article to help people identify if they have sciatica. Either way if this is still a problem no online advice will substitute a visit to a physiotherapist or doctor. Here is the article on sciatica and back pain. Hope it clarifies a few things for you