What is idiopathic intracranial hypertension and what can it cause left sided headaches

IIH: It's a disorder where elevated pressure in the head can cause vision loss & headache. Left-sided headaches suggest migraine more than IIH. If IIH, headache should be worst upon awakening. Diagnosis shouldn't be made without seeing an ophthalmologist to confirm papilledema and to perform Humphrey Visual Fields. I have patients see ophtho before doing spinal tap.