Clicking in the back of my head.

I have this ticking/ clicking for the past week and it don’t hurt or anything just annoying. It happens more of a morning then don’t happen as often during the day. I’m just a bit worried if it is something serious... or if it is just one of those things that come and go? 

Thank you all in advance.

Do you have any kind of stress? Because it may be due to some stress or tension.