This morning - suddenly - I started having lower left side back pain. It was not from a sprain or lifting, just a consistent pain that movement, ointments, ice or heat will change it. It feels like a kidney stone (had one two years ago) only this time it is on the left side, last time the right. Can that shift happen? Left then right?
Yes. It can happen. It may not be kidney stone always though. Get yourself examined by a physician if it persists.