The authors present a large retrospective review cohort of consecutive patients diagnosed or presumed idiopathic intracranial hypertension (IIH) over a three-year period at a single tertiary centre. Patients on medication with a known aetiology for IIH were excluded. The cohort was divided by whether their diagnosis had been incidental or after seeking medical care for symptoms of IIH. Demographics, height, weight, neuro-ophthalmic examination including visual acuity, visual fields, OCT and T1 MRI images were extracted. Of the 186 patients included the majority were female (96%). Two fifths of the cohort had incidental findings, with no differences regarding BMI or age between the groups. A small proportion of the incidental group were asymptomatic. This group was less likely to report common symptoms of headache, transient vision loss or diplopia, but more than half reported symptoms linked to IIH when questioned. The incidental group also had better visual acuity, visual field and OCT findings in comparison to the symptomatic group. The natural history of the disease course of the two groups is presented and included differences in treatment received. This study highlights the requirement of careful optic nerve examination even in the absence of symptom reporting. The authors suggest that these two different presentation methods could be a useful risk stratification method.