Chiari is a neurological disorder in which the skull of a person is too small for his brain to accomodate.
Because there is not enough room, the bottom part of the cerebellum pushes through the foram magnum onto the brain stem and spinal cord causing compression.
Compression causes a block in cerebral spinal fluid to the brain, and pressure build up. The pressure is not a 'headache' , it is a blockage of fluid to the brain. There is no cure. Chiari can affect every part of the body because everything is controlled by the brain stem.
Chiari is progressive. Surgery is to stop progression, but only has a 50/50 chance of improving symptoms already present. Chiari can paralyze the affected person, chiari can suppress your breathing if brainstem damage is extensive.
Chiari comes with a lot of connecting conditions such as elhers danlos, syringomyelia, iih and POTS to name a few Chiari will forever be part of the life, and it isn't just a "headache," There are over 150 symptoms that can go with chiari and comorbid conditions.
Chiari is not well known in the medical community but sharing info helps it become more well known. Be your own advocate, and fight for the care you deserve.