Headache is one of the most common clinical symptoms and complaints, and almost everyone will experience headache in their lifetime. Headache is caused by the stimulation of nociceptive sensory nerve endings in the head and neck, which generates abnormal nerve impulses to the brain. These headache patients need special attention. 1. The first or most severe headache – subarachnoid emergence, cerebral hemorrhage, arterial entrapment For example, if some patients describe a headache that has never occurred in their life, or a severe headache that is different from previous headache attacks, subarachnoid hemorrhage or cerebral hemorrhage should be highly suspected, and a head CT examination should be performed as soon as possible to aid in the diagnosis. 2.Progressive aggravation of subacute headache – encephalitis or meningitis, brain tumor, cerebral arteritis This kind of headache manifests as slowly aggravating, and the pain becomes more severe day by day, and it needs to pay attention to whether there is intracranial tumor, and if it is accompanied by fever, diarrhea and other infection symptoms, it needs to be identified by specialist examination whether there is encephalitis or meningitis. The incidence of primary headache decreases significantly in patients older than 50 years old, but the incidence of tumor, hypertensive cerebral hemorrhage, cerebral infarction and other diseases increases significantly, so these patients need to be carefully identified to exclude malignant headache. Therefore, these patients need to be carefully identified to exclude malignant headache. 4.Headache with cognitive function decline and personality change – encephalitis, meningitis, brain tumor The temporal lobe is the brain lobe that manages the cognitive function and personality of a person, if lesions occur in the temporal lobe, patients can have memory decline, learning ability loss, personality change, etc. Most patients with encephalitis will have temporal lobe damage; others such as temporal lobe tumor will also have the above symptoms. 5.Patients with malignant tumor presenting with headache – brain metastasis patients who have suffered from malignant tumor in the past, if they gradually develop headache, they need to pay special attention to whether there is intracranial metastasis of malignant tumor, so it is also very important to clarify the past medical history for consultation. 6.Headache with local neurological signs – cerebral infarction, cerebral hemorrhage, brain tumor Some patients have headache with poor speech, weakness of limb activities, double vision, numbness of limbs, etc. With these symptoms, it is highly suspected that there is cerebral nerve damage, cerebral infarction, cerebral hemorrhage, etc., which should be paid special attention. 7. Headache with epilepsy – encephalitis, brain tumor 8. Intractable headache with ineffective medication The pain can be relieved for a short period of time after the application of pain medication, but soon relapses, indicating that there may be persistent irritating lesions in the skull, and it is necessary to consult a specialist as soon as possible for clarification.