I have a chronic dull headache that won't go away (trust me i've had a comprehensive neuro workup), I've noticed that when I yawn "hold the yawn hard" where the ears are cleared, the pressure in my head eases up, and also if I hold my nose and blow air into my ears it feels better too (not a valsalva, just talking about the pressure within the nose and ears only). I have a deviated septum and feeling of a constantly blocked nose, and my head pressure is absuloutely constant and diffuse frontal / forehead region.