Sinus drainage & movement can cause one-sided headaches to come & go due to pressure changes in the sinus canals. As the canal fills up, if you change position, it will drain somewhere else, then that area fills up... mild decongestants might ease that feeling.
Also, in your ears are tiny crystalline structures that help determine your orientation in relation to your environment. A friend of mine had one break off & she was dizzy & had trouble staying upright until they were able to go in & remove it - the disorientation caused odd headaches for her, too.