Can sinuses cause burst of pain under the scalp? the outer layer of the scalp doesnt hurt. when my sinus drain the pain goes away. if not. what can?

Sinus headache: Sinus pressure and congestion can cause a rather strong headache which seems to feel like it’s inside your forehead. Not an all-over headache, but under the forehead. This is also a location for migraine and tension headaches.

Sort of: "Some studies have shown that up to 90 % of sinus headaches are actually migraines. " I've seen those studies, they're wrong because they assume particular cause/effect models that we KNOW are wrong. we know that migraine is a ping-pong between vessel inflammation and nerve stimulation. With each causing both. If you have something triggering BOTH, yeah, well, obviously sinus can trigger migraine.