Although there are many causes of headache during pregnancy, till proved otherwise, you should first consider that a headache could be due to the severe form of hypertension. Brain oedema (swelling due to fluid collecting around the brain) and increased pressure inside the skull (the medical name for the skull is the cranium, so doctors call this intracranial pressure) are the major reasons for the headache in severe pre-eclampsia.

Last modified: Friday, 11 July 2014, 1:14 PM