Ever since a young kid, as long as I can remember, I have had a intense discomfort in my head, similar to pain but not quite pain, whenever my head was near an object such as a wall or a confined space. This meant whenever I was young and sleeping in a bunk bed I would have to choose the top bed because if I was in the bottom bed my head would be too close to the solid wood above me and would produce a strange pressure like sensation. 

Does anyone know what this could be? It has been bugging me over the last week or so, and I've had to pull my bed away from the wall so I was not close to any solid objects when I slept otherwise the pressure would build in my mind. 

I've probably had this for about 15-20 years. As I say, it's been going on as long as I can remember, well into childhood. 

I looked into clostrapobia but that seems to be a completely different thing that doesn't cause intense sensations of pressure.