https://link.springer.com/article/10.1186/s10194-021-01241-7?fbclid=IwAR2RliqmLQX3xtyAvpBvcofq7svxMtSZ14XLTib0VerS8-Mj833trAAVE4k

It can take up to 10 years for people with cluster headache get the correct diagnosis! Education (patient and healthcare professionals) is needed to reduce this unacceptable time.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4812802/?fbclid=IwAR3Ut0HCYd8HTFoB2Ah6lGnrktF8fUjTjmlNuX1k3Bo_NbL0HB2zb4SuJzo