Unexplained headache should see neurology, headache is a common symptom of neurology, there are many causes of headache, we should first exclude secondary headache. If the headache is caused by cerebrovascular disease, if the headache suddenly appears, with explosive headache, accompanied by nausea, vomiting, neck stiffness, we should first consider subarachnoid hemorrhage. Patients with cerebral hemorrhage can also present with headache, which can be accompanied by hemiparesis of the limbs, crooked mouth, unfavorable speech, and in severe cases, unconsciousness. Ophthalmologic and ophthalmologic diseases can present headache, such as glaucoma, sinusitis. Traumatic brain injury, such as concussion, subdural hematoma, epidural hematoma, cerebral contusion can cause headache, but this has a more definite history of trauma. Cerebral neuralgia, such as trigeminal neuralgia, occipital neuralgia, auricular major neuralgia, and pharyngeal neuralgia. Infections of the central nervous system, such as meningitis and encephalitis, can cause headaches, often accompanied by signs of meningeal irritation, fever, and in severe cases, some psychiatric symptoms. Brain tumors tend to cause headaches that are a chronic headache that gets progressively worse, most often seen in gliomas, meningiomas, and brain metastases. Extracranial infections, such as infections of the respiratory tract, urinary system, biliary system, as well as fever caused by various other causes of infection, can be accompanied by headache symptoms. Therefore, we must exclude these causes of secondary headache from the diagnosis of headache. If the above causes are excluded, there are some other common causes of headache in neurology, such as migraine, tension headache, low cranial pressure headache and cluster headache. So no matter what the cause of the headache is, the first step should be to go to the neurology department for appropriate screening and differential diagnosis.