Editing Headache (section)

=== Secondary ===
{{More citations needed section|date=February 2021}}
Headaches may be caused by problems elsewhere in the head or neck. Some of these are not harmful, such as [[cervicogenic headache]] (pain arising from the neck muscles). The excessive use of painkillers can paradoxically cause worsening [[painkiller headache]]s.<ref name=SIGN /><ref name="NHS">{{cite web |title=Headaches |url=https://www.nhs.uk/conditions/headaches/ |website=nhs.uk |language=en |date=8 January 2018}}</ref>

More serious causes of secondary headaches include the following:<ref name="Goadsby" />
* [[meningitis]]: [[inflammation]] of the meninges which presents with fever and meningismus, or stiff neck
* [[Stroke|ischemic stroke]] or a previous stage of the same
* [[Stroke|hemorragic stroke]] or a previous stage of the same
* [[intracranial hemorrhage]] (bleeding inside the brain) because of any origin
* [[subarachnoid hemorrhage]] (with acute, severe headache, stiff neck without fever) because of any origin
* [[intraparenchymal hemorrhage]] (with headache only) because of any origin
* [[ruptured aneurysm]] or [[aneurysm]]
* [[brain tumor]] (a form of cancer): dull headache, worse with exertion and change in position, accompanied by nausea and vomiting. Often, the person will have nausea and vomiting for weeks before the headache starts.
* [[temporal arteritis]]: inflammatory disease of arteries common in the elderly (average age 70) with fever, headache, weight loss, jaw claudication, tender vessels by the temples, polymyalgia rheumatica
* [[Glaucoma|acute closed-angle glaucoma]] (increased pressure in the eyeball): a headache that starts with eye pain, blurry vision, associated with nausea and vomiting. On physical exam, the person will have red eyes and a fixed, mid-dilated pupil.
* [[arteriovenous malformation]]
* post-ictal headaches: Headaches that happen after a convulsion or other type of seizure, as part of the period after the seizure (the [[post-ictal]] state)
* [[traumatic brain injury]]

[[Gastrointestinal disease|Gastrointestinal disorders]] may cause headaches, including [[Helicobacter pylori]] infection, [[celiac disease]], [[non-celiac gluten sensitivity]], [[irritable bowel syndrome]], [[inflammatory bowel disease]], [[gastroparesis]], and [[List of hepato-biliary diseases|hepatobiliary disorders]].<ref name=LionettiFrancavilla2010>{{cite journal | vauthors = Lionetti E, Francavilla R, Pavone P, Pavone L, Francavilla T, Pulvirenti A, Giugno R, Ruggieri M | title = The neurology of coeliac disease in childhood: what is the evidence? A systematic review and meta-analysis | journal = Developmental Medicine and Child Neurology | volume = 52 | issue = 8 | pages = 700–707 | date = August 2010 | pmid = 20345955 | doi = 10.1111/j.1469-8749.2010.03647.x | type = Systematic review and meta-analysis | s2cid = 205611320 | doi-access = free }}{{open access}}</ref><ref name=AzizHadjivassiliou2015>{{cite journal | vauthors = Aziz I, Hadjivassiliou M, Sanders DS | title = The spectrum of noncoeliac gluten sensitivity | journal = Nature Reviews. Gastroenterology & Hepatology | volume = 12 | issue = 9 | pages = 516–526 | date = September 2015 | pmid = 26122473 | doi = 10.1038/nrgastro.2015.107 | type = Review | s2cid = 2867448 }}</ref><ref name=CamaraLemarroyRodriguezGutierrez2016>{{cite journal | vauthors = Cámara-Lemarroy CR, Rodriguez-Gutierrez R, Monreal-Robles R, Marfil-Rivera A | title = Gastrointestinal disorders associated with migraine: A comprehensive review | journal = World Journal of Gastroenterology | volume = 22 | issue = 36 | pages = 8149–8160 | date = September 2016 | pmid = 27688656 | pmc = 5037083 | doi = 10.3748/wjg.v22.i36.8149 | type = Review | doi-access = free }}</ref> The treatment of the gastrointestinal disorders may lead to a remission or improvement of headaches.<ref name=CamaraLemarroyRodriguezGutierrez2016 />

Migraine headaches are also associated with [[Cyclic Vomiting Syndrome]] (CVS). CVS is characterized by episodes of severe vomiting, and often occur alongside symptoms similar to those of migraine headaches (photophobia, abdominal pain, etc.).<ref>{{cite journal | vauthors = Hasler WL, Levinthal DJ, Tarbell SE, Adams KA, Li BU, Issenman RM, Sarosiek I, Jaradeh SS, Sharaf RN, Sultan S, Venkatesan T | title = Cyclic vomiting syndrome: Pathophysiology, comorbidities, and future research directions | journal = Neurogastroenterology and Motility | volume = 31 | issue = Suppl 2 | pages = e13607 | date = June 2019 | pmid = 31241816 | pmc = 6899706 | doi = 10.1111/nmo.13607 }}</ref>