Question
I woke up this morning and turned over and I felt and heard my ribs crack or cave in. Can you tell me what causes that to happen and can it be fixed.  

Answer
It is possible that you misaligned a rib with the rolling over motion.  If conditions are just right, it is very easy to do.  Usually, with a rib misalignment, you can have pain with a deep breath.  I would suggest finding a good chiropractor to assess it and treat it, and also to rule out a fracture.