Hello, for the past year, often when I take naps throughout the day I'll wake up to a heavy pulsating vibrations in my head that every time becomes stronger and more painful until I wake up. It's like an engine reving, and with each spike of the rpm's there's a painful pulsating sensation. I'm not on any medications and am really just curious what could be the cause of this? Could it just be the way I lay my head down cutting off circulation or what?