| Migraine |
| Tension-type headache |
| Cluster headache |
| Medication rebound and withdrawal headache |
| Carotid or vertebral artery dissection |
| Intracranial hemorrhage (eg, arteriovenous malformation, aneurysm, trauma) |
| Cerebral venous sinus thrombosis |
| Preeclampsia/eclampsia |
| Benign intracranial hypertension |
| Post dural puncture headache |
| Mass lesion/tumor |
| Primary thunderclap headache |
| Pituitary apoplexy |
| Meningioma |
| Reversible cerebral vasoconstriction syndrome |
| Reversible posterior encephalopathy syndrome |
| Primary angiitis of the central nervous system |
| Infection (eg, sinusitis, meningitis, encephalitis) |
| Stroke |
