When I lie on my back, my right cheek about a 1/4" above my lower right jaw swells up. As soon as I stand up, the swelling subsides. If I lay on my stomach or sides there is no swelling at all. If I bend over for more than say 5 seconds to pick something up, my face swells in the same spot but subsides as soon a I stand up. I'm thinking this could be sinus related. I do have very bad post nasal drip but really no other problems sinus related. I dont have a cold or fever either. Does anybody have any ideas to what might be causing this.