Headache is a symptom, not a disease. There are many causes of headache. We often divide headache into two categories. One is primary headache, which includes migraine, tension headache and cluster headache. The other is secondary headache, which can be caused by head or neck trauma, intracranial tumor, cerebrovascular disease, congenital heart disease, intracranial infection, drugs, hypertension, glaucoma, sinusitis, mental disorders and so on.

Clinical manifestations of headache are varied. The location can be unilateral or bilateral, local or the whole head pain. The character of headache can be distending, dull, pressing, throbbing, pinprick, burning, thunderclap and so on. The duration varies from a few seconds to a few weeks, and some even have long-term daily headaches. The accompanying symptoms are varied due to different etiology, which can have nausea, vomiting, fever, blurred vision, sensitivity to lights and/or sound, unilateral lacrimation /runny nose, etc.

Auxiliary examination: hematology examination; neuroimaging examination including head MRI, head and neck MRA/CTA, MRV, head CT; TCD; EEG; transesophageal cardiac ultrasound; lumbar puncture; DSA, etc.