International Classification of Headache Disorders

The International Classification of Headache Disorders (ICHD) is a detailed hierarchical classification of all headache-related disorders published by the International Headache Society. It is considered the official classification of headaches by the World Health Organization, and, in 1992, was incorporated into the 10th edition of their International Classification of Diseases (ICD-10). Each class of headache contains explicit diagnostic criteria—meaning that the criteria include quantities rather than vague terms like several or usually—that are based on clinical and laboratory observations.

The ICHD was first published in 1988 (now known as the ICHD-1). A second version, the ICHD-2, was published in 2004. The most current version, ICHD-3, was published in 2018.

Hierarchy

Primary headaches

ICHD 1, ICD10 G43: Migraine

Migraine without aura

Migraine with aura

Childhood periodic syndromes that are commonly precursors of migraine

Retinal migraine

Complications of migraine

Migraine-triggered seizure

Probable migraine

ICHD 2, ICD10 G44.2: Tension-type headache (TTH)

Infrequent episodic tension-type headache

Frequent episodic tension-type headache

Chronic tension-type headache

Probable tension-type headache

ICHD 3, ICD10 G44.0: Cluster headache and other trigeminal autonomic cephalalgias

Cluster headache

Paroxysmal hemicrania

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)

Probable trigeminal autonomic cephalalgia

ICHD 4, ICD10 G44.80: Other primary headaches

Primary stabbing headache

Primary cough headache

Primary exertional headache

Primary headache associated with sexual activity

Hypnic headache

Primary thunderclap headache

Hemicrania continua

New daily persistent headache (NDPH)

Secondary headaches

ICHD 5, ICD10 G44.88: Headache attributed to head and/or neck trauma

Acute post-traumatic headache

Acute post-traumatic headache attributed to moderate or severe head injury

Acute post-traumatic headache attributed to mild head injury

Chronic post-traumatic headache

Chronic post-traumatic headache attributed to moderate or severe head injury

Chronic post-traumatic headache attributed to mild head injury

Acute headache attributed to whiplash injury

Chronic headache attributed to whiplash injury

Headache attributed to traumatic intracranial haematoma

Headache attributed to epidural haematoma

Headache attributed to subdural haematoma

Headache attributed to other head and/or neck trauma

Acute headache attributed to other head and/or neck trauma

Chronic headache attributed to other head and/or neck trauma

Post-craniotomy headache

Acute post-craniotomy headache

Chronic post-craniotomy headache

ICHD 6, ICD10 G44.81: Headache attributed to cranial or cervical vascular disorder

Headache attributed to ischaemic stroke or transient ischaemic attack

Headache attributed to ischaemic stroke (cerebral infarction)

Headache attributed to transient ischaemic attack (TIA)

Headache attributed to non-traumatic intracranial haemorrhage

Headache attributed to intracerebral haemorrhage

Headache attributed to subarachnoid haemorrhage (SAH)

Headache attributed to unruptured vascular malformation

Headache attributed to saccular aneurysm

Headache attributed to arteriovenous malformation (AVM)

Headache attributed to dural arteriovenous fistula

Headache attributed to cavernous angioma

Headache attributed to encephalotrigeminal or leptomeningeal angiomatosis (Sturge Weber syndrome)

Headache attributed to arteritis

Headache attributed to giant cell arteritis (GCA)

Headache attributed to primary central nervous system (CNS) angiitis

Headache attributed to secondary central nervous system (CNS) angiitis

Carotid or vertebral artery pain

Headache or facial or neck pain attributed to arterial dissection

Post-endarterectomy headache

Carotid angioplasty headache

Headache attributed to intracranial endovascular procedures

Angiography headache

Headache attributed to cerebral venous thrombosis (CVT)

Headache attributed to other intracranial vascular disorder

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)

MELAS (eitochondrial encephalopathy, lactic acidosis and stroke-like episodes)

Headache attributed to benign angiopathy of the central nervous system

Headache attributed to pituitary apoplexy

ICHD 7, ICD10 G44.82: Headache attributed to non-vascular intracranial disorder

Headache attributed to high cerebrospinal fluid pressure

Headache attributed to idiopathic intracranial hypertension (IIH)

Headache attributed to intracranial hypertension secondary to metabolic, toxic or hormonal causes

Headache attributed to intracranial hypertension secondary to hydrocephalus

Headache attributed to low cerebrospinal fluid pressure

Post-dural puncture headache

CSF fistula headache

Headache attributed to spontaneous (or idiopathic) low CSF pressure

Headache attributed to non-infectious inflammatory disease

Headache attributed to neurosarcoidosis

Headache attributed to aseptic (non-infectious) meningitis

Headache attributed to other non-infectious inflammatory disease

Headache attributed to lymphocytic hypophysitis

Headache attributed to intracranial neoplasm

Headache attributed to increased intracranial pressure or hydrocephalus caused by neoplasm

Headache attributed directly to neoplasm

Headache attributed to carcinomatous meningitis

Headache attributed to hypothalamic or pituitary hyper- or hyposecretion

Headache attributed to intrathecal injection

Headache attributed to epileptic seizure

Hemicrania epileptica

Post-seizure headache

Headache attributed to Chiari malformation type I (CM1)

Syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL)

Headache attributed to other non-vascular intracranial disorder

ICHD 8, ICD10 G44.4 or G44.83: Headache attributed to a substance or its withdrawal

Headache induced by acute substance use or exposure

Nitric oxide (NO) donor-induced headache

Immediate NO donor-induced headache

Delayed NO donor-headache

Phosphodiesterase (PDE) inhibitor-induced headache

Carbon monoxide-induced headache

Alcohol-induced headache.

Immediate alcohol-induced headache

Delayed alcohol-induced headache

Headache induced by food components and additives

Monosodium glutamate-induced headache

Cocaine-induced headache

Cannabis-induced headache

Histamine-induced headache

Immediate histamine-induced headache

Delayed histamine-induced headache

Calcitonin gene-related peptide (CGRP)-induced headache

Immediate CGRP-induced headache

Delayed CGRP-induced headache

Headache as an acute adverse event attributed to medication used for other indications

Headache attributed to other acute substance use or exposure

Medication-overuse headache (MOH)

Ergotamine-overuse headache

Triptan-overuse headache

Analgesic-overuse headache

Opioid-overuse headache

Combination analgesic-overuse headache

Medication-overuse headache attributed to combination of acute medications

Headache attributed to other medication overuse

Probable medication-overuse headache

Headache as an adverse event attributed to chronic medication

Exogenous hormone-induced headache

Headache attributed to substance withdrawal

caffeine-withdrawal headache

opioid-withdrawal headache

Oestrogen-withdrawal headache

Headache attributed to withdrawal from chronic use of other substances

ICHD 9, ICD10 G44.821 or G44.881: Headache attributed to infection

Headache attributed to intracranial infection

Headache attributed to bacterial meningitis

Headache attributed to lymphocytic meningitis

Headache attributed to encephalitis

Headache attributed to brain abscess

Headache attributed to subdural empyema

Headache attributed to systemic infection

Headache attributed to systemic bacterial infection

Headache attributed to systemic viral infection

Headache attributed to other systemic infection

Headache attributed to HIV/AIDS

Chronic post-infection headache

Chronic post-bacterial meningitis headache

ICHD 10, ICD10 G44.882: Headache attributed to disorder of homeostasis

Headache attributed to hypoxia and/or hypercapnia

High-altitude headache

Diving headache

Sleep apnoea headache

Dialysis headache

Headache attributed to arterial hypertension

Headache attributed to phaeochromocytoma

Headache attributed to hypertensive crisis without hypertensive encephalopathy

Headache attributed to hypertensive encephalopathy

Headache attributed to pre-eclampsia

Headache attributed to eclampsia

Headache attributed to acute pressor response to an exogenous agent

Headache attributed to hypothyroidism

Headache attributed to fasting

Cardiac cephalalgia

Headache attributed to other disorder of homoeostasis

ICHD 11, ICD10 G44.84: Headache or facial pain attributed to disorder of cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other facial or cranial structures

Headache attributed to disorder of cranial bone

Headache attributed to disorder of neck

Cervicogenic headache

Headache attributed to retropharyngeal tendonitis

Headache attributed to craniocervical dystonia

Headache attributed to disorder of eyes

Headache attributed to acute glaucoma

Headache attributed to refractive errors

Headache attributed to heterophoria or heterotropia (latent or manifest squint)

Headache attributed to ocular inflammatory disorder

Headache attributed to disorder of ears

Headache attributed to rhinosinusitis

Headache attributed to disorder of teeth, jaws or related structures

Headache or facial pain attributed to temporomandibular joint (TMJ) disorder

Headache attributed to other disorder of cranium, neck, eyes, ears, nose, sinuses,

teeth, mouth or other facial or cervical structures

ICHD 12, ICD10 R51: Headache attributed to psychiatric disorder

Headache attributed to somatization disorder

Headache attributed to psychotic disorder

Cranial neuralgias, central and primary facial pain and other headaches

ICHD 13, ICD10 G44.847, G44.848, or G44.85: Cranial neuralgias and central causes of facial pain

ICHD 13.1, ICD10 G44.847: Trigeminal neuralgia

Glossopharyngeal neuralgia

Nervus intermedius neuralgia

Superior laryngeal neuralgia

Nasociliary neuralgia

Supraorbital neuralgia

Other terminal branch neuralgias

Occipital neuralgia

Neck-tongue syndrome

External compression headache

Cold-stimulus headache

Constant pain caused by compression, irritation or distortion of cranial nerves or upper cervical roots by structural lesions

Optic neuritis

Ocular diabetic neuropathy

Head or facial pain attributed to herpes zoster

Head or facial pain attributed to acute herpes zoster

Post-herpetic neuralgia

Tolosa–Hunt syndrome

Opthalamoplegic migraine

Central causes of facial pain

Anaesthesia dolorosa

Central post-stroke pain

Facial pain attributable to multiple sclerosis

Persistent idiopathic facial pain (the IHS's preferred term for atypical facial pain)

Burning mouth syndrome

Other cranial neuralgia or other centrally mediated facial pain

ICHD 14, ICD10 R51: Other headache, cranial neuralgia, central or primary facial pain

Headache not elsewhere classified

Headache unspecified