Cracking sound in base of skull/neck area. Is this common?? This seems to have been occuring the past couple of weeks, usually about 10 times a day. It happens at odd times, just sitting still, when I yawn, when I turn my head, etc. Could this be arthritis or something more serious? My hairdresser has also noticed a bump area on the left side on the back of my neck. Could all of this be related?