More feelings.

I have noticed for about the last week that, when I properly breathe to dantien, I have a sense that something is moving down from mingmen and up from mingmen, both vertically. The upward movement goes all the way up my neck and stops there. It feels as though my breath is filling up the area around my spine from mingmen up and mingmen down the whole thing seems to inflate. This concerned me because I thought that there was not supposed to be any pressure in the neck. The feeling occurs during the inhale. The fuller the breath gets the farther up and down the fullness travels. Is this the breath wave?