Permanent vision loss and visual impairment from papilledema are among the most serious complications of raised intracranial pressure. Papilledema is optic disc edema caused by raised intracranial pressure secondary to any cause and should be differentiated from optic disc edema from other acute anterior optic neuropathies and from pseudopapilledema. The diagnosis is traditionally made on fundus examination of patients with headaches or visual complaints. Modern routine ocular imaging permits quantification of papilledema and is useful for follow-up of such patients. Most patients with papilledema have good visual outcome, but the issue is to rapidly identify and treat those who are at risk of permanent vision loss. It remains unclear how initially optic disc swelling with preserved vision, also seen in other acute anterior optic neuropathies, can build up to permanent vision loss. The pathophysiology of papilledema is directly related to the degree of intracranial pressure, but several clinical observations, such as raised intracranial pressure without papilledema, and asymmetric papilledema, suggest variable vulnerability of the optic nerves to raised intracranial pressure. In addition, emerging theories about cerebrospinal fluid absorption in the subarachnoid spaces of the brain and the optic nerves might shed light on new pathophysiological mechanisms. Delays in diagnosis of papilledema are partly explained by (i) the fact that many patients present with headaches but no visual complaints so ophthalmology is not involved right away; (ii) the fact that clinical fundus examination is rarely performed by non-ophthalmologists; and (iii) in patients diagnosed with papilledema, the urgency of expedited investigations and referral might not be acknowledged. The emergence of nonmydriatic fundus photography in emergency departments and neurology clinics holds the promise of earlier detection and management of papilledema to prevent permanent vision loss. From a therapeutic point of view, treatment of papilledema and IIH and some causes of secondary intracranial hypertension should not be overlooked in patients with severe papilledema in addition to the treatment of the cause. In such patients, early evaluation of the risk of vision loss and multidisciplinary discussions involving ophthalmology are important to start medical or surgical treatment aimed at lowering intracranial pressure and preserve vision.