Nerves regenerate at a pace of 2 to 4 millimeters per day, depending on how the nerve was injured, the National Center for Biotechnology Information states. For example, a crushed nerve regenerates faster than a sectioned nerve.
The Department of Neurosurgery at New York University Langone Medical Center goes on to say that although research is being conducted to create medications that can speed up nerve regeneration, there are no drugs or growth factors viable as of 2014 to help with this process. There are surgeries available to repair nerve damage as well as nerve grafting and nerve transfers.
According to the Journal of Clinical Investigation, the chances of regenerating nerves and recovering motor skills are improved if surgery is performed right away. This journal also says that a heat shock may improve nerve repair, acting as a turbocharge to keep cells in a state that supports regeneration.
Science Daily states that some nerves never regenerate and heal fully. For example, those with motor nerve damage usually never recover full function of the muscle. The problem is that the regeneration is so slow that the nerves lose the ability to communicate with the muscle because they haven't been stimulated for such a long period of time.