If there is a history of previous headache attacks, the headache is located in the orbital, periorbital, frontal, or temporal regions, the pain stops suddenly or relieves slowly, the duration varies from 15 to 180 minutes, and the nature of the headache is colic, tearing, or burning pain, accompanied by conjunctival congestion, nasal congestion, tearing, nausea, and vomiting, it is possible that the headache is a cluster headache. Cluster headache is a primary headache disorder, the exact cause of which is not known, and is mainly treated with symptomatic pain relief with zolmitriptan and sumatriptan. If a patient has no previous history of headache attacks and suddenly develops these symptoms, a cranial CT or MRI should first be performed to rule out subarachnoid hemorrhage. Subarachnoid hemorrhage is an acute hemorrhagic cerebrovascular disease. Patients mainly present with severe headache that is unbearable, while nausea and vomiting may occur, and signs of meningeal irritation may be present, and cranial CT examination can make a clear diagnosis.