Here's what David Buchholz MD has to say (from John Hopkins University School of Medicine) about it in "Heal Your Headache":
(This is a summary - not quoted from the book)
This falls under the "Myth" of sinus headache -
- the mucosu membranes that line your nose and sinuses are loaded with blood vessels.
- when migraine causes blood vessels of the head to become swollen, its favourite target is the nose and sinuses.
- the swelling and inflammation of blood vessels there produces congestion, pressure, stuffiness, postnasal drip, and pain.
- you and your doc don't realise this is migraine and, instead, think it is allergy, infection or a structural abnormality afflicting your sinuses
- migraine is behind this most of the time.
You might have this going on C&R. Migraine seems to occur - and possibly be at the root - in many of us long-term dizzy sufferers.
Scott