About 90% of the patients suffer from idiopathic headaches, for example, migraine or tension headaches, which are treated according to guidelines. An [[acute headache]] can however also be a symptom of a serious primary disease, such as [[subarachnoid hemorrhage]], arterial dissection, cerebral infarction, cerebral venous thrombosis or acute glaucoma. Patients with suspected symptomatic headaches must be immediately referred to a specialist or hospital for further diagnosis and therapy
((Pöllmann W, Förderreuther S. [Acute headaches--when to treat immediately, when
to wait]. MMW Fortschr Med. 2007 May 21;149 Suppl 2:61-4. Review. German. PubMed 
PMID: 17724970.
)).
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Patients with [[optic chiasma cavernous malformation]] typically present with [[chiasmal apoplexy]], characterized by sudden [[visual loss]], [[acute headache]]s, [[retroorbital pain]], and nausea
((Liu JK, Lu Y, Raslan AM, Gultekin SH, Delashaw JB Jr. Cavernous malformations 
of the optic pathway and hypothalamus: analysis of 65 cases in the literature.
Neurosurg Focus. 2010 Sep;29(3):E17. doi: 10.3171/2010.5.FOCUS10129. Review.
PubMed PMID: 20809758.
)).