In cases of isolated headache with a normal neurologic exam, imaging is usually not appropriate. However, headaches with secondary features may require further imaging:

• Sudden onset severe (thunderclap) headache
• Primary trigeminal autonomic cephalgias (e.g. cluster headache)
• Headache with features of intracranial hypertension
• Headache with features of intracranial hypotension
• Headache with new onset in pregnancy
• Headache with “red flags”