I have the same, occasional feeling of a bubble in my head, no headaches or pain, but some sensation of pressure as well. I don't know if the feeling
triggers anxiety or if I feel anxious because of the bubble feeling. It's not
quite dizziness, but a sensation of floating No doctor has ever given me an answer on that one either.
Maybe it's related to the fact that when I open my mouth,
my jaw on my right side clicks, maybe due to some cranial/structural factor. I also notice it when my sinus is not clear. All I can say is that I first noticed
this sensation in 1997 after I was stung multiple times by bees, and when
I was feeling anxious about the stings