I had carpal tunnel surgery in 2012 but now symptoms return. what is going on? should i be concerned?

Recurrent carpal tun: All problems can recur if one resumes the activity which created the problem in the first place. You should be seen by an upper extremity specialist. Many times the diagnosis needs to be accurate. I.e. One may have compression of the nerves from the neck and or brachial plexus , which may also need to be treated. Be sure that conservative treatment is initiated first . Perhaps a second opinion .