Table 2- 1 International Headache Society classification system (Headache Classification Committee, 1988)

A. Primary headache disorders

1. Migraine
  1.1 Migraine without aura
  1.2 Migraine with aura
  1.3 Ophthalmoplegic
  1.4 Retinal migraine
  1.5 Childhood periodic syndromes that may be precursors to or associated with migraine
  1.6 Complications of migraine
  1.7 Migrainous disorder not fulfilling above criteria

2. Tension-type headache
  2.1 Episodic
  2.2 Chronic
  2.3 Headache not fulfilling above criteria

3. Cluster headache and chronic paroxysmal hemicrania

  3.1 Cluster headache
   3.1.1 Periodicity undetermined
   3.1.2 Episodic
   3.1.3 Chronic
  3.2 Chronic paroxysmal hemicrania
  3.3 Cluster headache-like disorder not fulfilling above criteria

4. Miscellaneous headaches unassociated with structural lesion
  4.1 Idiopathic stabbing headache
  4.2 External compression headache
  4.3 Cold stimulus headache
  4.4 Benign cough headache
  4.5 Benign exertional headache
  4.6 Headache associated with sexual activity

B. Secondary headache disorders

5. Headache associated with head trauma
  5.1 Acute posttraumatic headache
  5.2 Chronic posttraumatic headache

6. Headache associated with vascular disorders
  6.1 Acute ischemic cerebrovascular disease
  6.2 Intracranial hematoma
  6.4 Unruptured vascular malformation
  6.5 Arteritis
  6.6 Carotid or vertebral artery pain
  6.7 Venous thrombosis
  6.8 Arterial hypertension
  6.9 Headache associated with other vascular disorder

7. Headache associated with nonvascular intracranial disorder
  7.1 High cerebrospinal fluid pressure
  7.2 Low cerebrospinal fluid pressure
  7.3 Intracranial infection
  7.4 Intracranial sarcoidosis and other noninfectious inflammatory diseases
  7.5 Headache related to intrathecal injections
  7.6 Intracranial neoplasm
  7.7 Headache associated with other intracranial disorder

8. Headache associated with substances or their withdrawal
  8.1 Headache induced by acute substance use or exposure
  8.2 Headache induced by chronic substance use or exposure
  8.3 Headache from substance withdrawal (acute use)
  8.4 Headache from substance withdrawal (chronic use)
  8.5 Headache associated with substances but with uncertain mechanism

9. Headache associated with noncephalic infection
  9.1 Viral infection
  9.2 Bacterial infection
  9.3 Headache related to other infection

10. Headache associated with metabolic disorder
  10.1 Hypoxia
  10.2 Hypercapnia
  10.3 Mixed hypoxia and hypercapnia
  10.4 Hypoglycemia
  10.5 Dialysis
  10.6 Headache related to other metabolic abnormality

11. Headache or facial pain associated with disorder of cranium, neck, eyes, ears, nose, sinuses, teeth, mouth, or other facial or cranial structures
  11.1 Cranial bone
  11.2 Neck
  11.3 Eyes
  11.4 Ears
  11.5 Nose and sinuses
  11.6 Teeth, jaws, and related structures
  11.7 Temporomandibular joint disease

12. Cranial neuralgias, nerve trunk pain, and deafferentation pain
  12.1 Persistent (in contrast to tic-like) pain of cranial nerve origin
  12.2 Trigeminal neuralgia
   12.2.1 Idiopathic trigeminal neuralgia
   12.2.2 Symptomatic trigeminal neuralgia
  12.3 Glossopharyngeal neuralgia
  12.4 Nervus intermedius neuralgia
  12.5 Superior laryngeal neuralgia
  12.6 Occipital neuralgia
  12.7 Central causes of head and facial pain other than tic douloureux
  12.8 Facial pain not fulfilling criteria in groups 11 or 12

13. Headache not classifiable

Editors: Silberstein, Stephen D.; Lipton, Richard B.; Dalessio, Donald J.