My left rib is feeling tender and hurts to move or sleep on. no injury. and i'm having some back pain in the lung area. any idea?

Have examination: There are several considerations. Without knowing it even by coughing you could have caused bruising or tendon problem in the intercostals or the rib. You could have a displace rib or a floating rib depending on location. You could also have a radicular pain . Pleuritic pain also has to be considered or even zoster if there is a rah. Go to your md to clarify.