Summary
Headache is a symptom commonly encountered in everyday clinical practice, and, according to the WHO, one of the ten most common causes of functional disability. It may be primary (e.g., tension-type headaches, migraine) or secondary (e.g., following head trauma or infections) in nature. Although most episodes of headache are harmless, potentially life-threatening causes (e.g., subarachnoid hemorrhage, meningitis) should always be considered. Identifying the cause of headaches is often difficult and requires a detailed clinical history as well as a thorough physical examination. Additional diagnostics, e.g., imaging, are only indicated if headaches persist despite treatment or if specific clinical features are present that are signs of an underlying disease. This article gives an overview of the most common types of headache and serves as a guide to diagnosing different headache disorders.
Approach
Approach to management
- Check vital signs.
- Perform focused history and examination.
- If red flags are present:
- Obtain brain imaging (either CT or MRI brain with and/or without contrast) based on the red flag symptoms. [1]
- Perform further targeted diagnostics (see below).
- If no red flags are present and suspicion for life-threatening causes is low:
- Perform a detailed history and clinical exam.
- Consider whether further diagnostic testing is necessary.
- Provide supportive care.
- Identify and treat the underlying cause.
Red flags for headache [1]
- Sudden-onset severe headache (e.g., ”thunderclap headache”)
- Fever
- Focal neurological deficits
- New headache at age > 50
- Progressively worsening headache
- Immunodeficiency (especially HIV)
- Seizures
- Meningeal signs
- Psychiatric symptoms
- Failure to respond to analgesics
- “Worst headache of my life”
- Visual deficits
- Pregnancy or postpartum period
- Signs of increased ICP (e.g., papilledema)
- Confusion or impaired level of consciousness
Life-threatening conditions [1]
- Intracranial hemorrhage: subarachnoid hemorrhage, epidural hemorrhage, intracerebral hemorrhage
- CNS infection: meningitis, encephalitis, brain abscess, subdural empyema
- Conditions causing increased ICP
- Hypertensive emergency
- Internal carotid artery dissection
- Vertebral artery dissection
- Ischemic stroke
- Pituitary apoplexy
- Carbon monoxide poisoning
- Cerebral venous sinus thrombosis
- Hypoglycemia
- Pre-eclampsia or eclampsia
- Non-life-threatening conditions requiring urgent attention:
Definition
- Headache is a pain related to irritation and/or inflammation of intracranial or extracranial structures with pain receptors (e.g., meninges, cranial nerves, blood vessels).
-
Primary headache: a headache that is not caused by another underlying condition [2]
- Includes migraine headache, tension headache, trigeminal autonomic cephalalgias (e.g., cluster headache)
- Secondary headache: a headache that is caused by another underlying condition (e.g., trauma, space-occupying lesion) [2]
Epidemiology
- Lifetime prevalence: > 90%, with female predominance (except cluster headache) [3]
-
Most common forms of headache [3]
- Tension-type headache: 40–80% of cases
- Migraine: 10% of cases
Epidemiological data refers to the US, unless otherwise specified.
Etiology
See “Differential diagnoses” below.
Clinical features
History of present illness
-
Timing
- Duration of a single episode
- Frequency
- Clinical course (e.g., chronic, acute)
-
Nature of the headache
- Localization
- Character
- Intensity
- Radiation of pain
- Severity (e.g., impact on patient's life)
-
Triggers and exacerbating factors
- Altered sleep-wake cycle
- Physical exertion
- Stress
- Certain types of food or alcohol
- Fluctuations in hormone levels: oral contraceptives; , menstruation
- Lying down or standing up
- Recent trauma
-
Associated symptoms
- Nausea/vomiting
- Horner syndrome
- Aura
- Photopsia, photophobia
- Neck stiffness
- Seizures
- Change in vision
- Lacrimation, rhinorrhea
- New skin lesions
- Allodynia of the head region
Past medical history, social history, and family history
- Past medical history (e.g., hypertension, hypothyroidism, seizures, migraine, infections)
- Medications (e.g., anticoagulants , analgesics, OCPs)
- Allergies
- Caffeine intake
-
Substance use
- Alcohol consumption
- Smoking
- Family history
Physical examination
-
Vital signs
- Blood pressure
- Presence of fever
-
HEENT
- Signs of trauma
- Auscultation for bruits
- Palpation of pericranial muscles
- Palpation of the temporal artery; and assessment of jaw movement
- Palpation along the course of the trigeminal nerve
- Examination of the teeth and oral cavity
- Examination of the eye and extraocular movements
- Assessment of cervical spine mobility
- Palpation of the sinuses
- Direct fundoscopy
-
Neurological
- Neurological examination for neurologic deficits
- Signs of meningism
- Abdomen: inspection and palpation of the abdomen
- Skin: : Evaluate for rash or signs of drug use.
Consider secondary life-threatening causes if red flags for headache are present!
Diagnostics
Approach [4]
- Diagnostic evaluation should be performed based on risk stratification and the suspected diagnosis.
- Low-risk headache: No routine laboratory tests or imaging are recommended.
- High-risk headache: Consider diagnostic workup based on the suspected diagnosis.
- Primary headache is a clinical diagnosis and typically does not require laboratory or imaging evaluation.
Risk stratification of headache [4][5]
Clinical features | |
---|---|
Low-risk headache |
|
High-risk headache |
|
Laboratory studies
- There are no routine recommended laboratory studies for headaches. Consider the following based on clinical suspicion:
Imaging [6]
- Indications
- For emergency neuroimaging
- Abnormal neurologic examination
- New, sudden-onset severe headache (e.g., thunderclap headache)
- Patients with HIV with a new type of headache
- For urgent (arranged prior to discharge) neuroimaging in the emergency department:
- Patients > 50 years old with a new type of headache but normal neurologic examination
- In all other situations, imaging should be considered based on the suspected diagnosis and risk stratification.
- For emergency neuroimaging
- Test of choice
- The initial test of choice is usually a head CT without contrast.
- See the table below for other imaging modalities to consider.
Recommended initial imaging modality for headache [7] | |||
---|---|---|---|
Initial test of choice | Alternatives | ||
Sudden-onset severe headache (i.e., thunderclap headache) |
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New headache with papilledema |
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| |
New or worsening headache related to head trauma or accompanied by red flags |
|
| |
New primary headache suspected to be of trigeminal autonomic origin (e.g., cluster headache) |
|
| |
Chronic headache with new features or change in character, severity, or frequency |
|
|
Additional diagnostics to consider [6]
- Lumbar puncture (LP) with CSF analysis: for suspected meningitis, suspected inflammatory process or malignancy, or if there is a high suspicion of SAH without proof on CT scan
- Tonometry: if increased intraocular pressure is suspected
- EEG: for any form of suspected seizures or complex migraine
- Temporal artery biopsy: if GCA is suspected
The diagnostic modality should be determined by the patient history and clinical presentation. Neuroimaging is usually not indicated for primary or low-risk headaches.
Primary headaches
Tension headache | Migraine headache | Cluster headache | |
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Sex | |||
Duration |
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Frequency |
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Localization |
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Character |
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Intensity |
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Additional symptoms |
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Triggers/exacerbating factors |
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Diagnostic findings |
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Acute management |
The typical migraine headache can be remembered by “POUND”: pulsatile, one-day duration, unilateral, nausea, disabling intensity.
Secondary headaches
Diagnosis | Clinical features | Diagnostic findings | Acute management |
---|---|---|---|
Meningitis [11][12][13] |
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Intracerebral hemorrhage [14][15] |
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Subarachnoid hemorrhage [16] |
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Subdural hematoma (SDH) |
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Epidural hematoma [17] |
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Cerebral venous sinus thrombosis [18] |
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Giant cell arteritis [20][21][22][23] |
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Hypertensive crises [24][25] |
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Ischemic stroke [26][27] |
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Intracranial space-occupying lesions (e.g., brain tumors) [28][29][30] |
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Concussion (e.g., mild traumatic brain injury) [31][32][33] |
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Trigeminal neuralgia [34][35] |
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Medication overuse headache |
|
|
Differential diagnoses
Primary headache
- Migraine
- Tension-type headache
- Trigeminal autonomic cephalalgias: cluster headaches, paroxysmal hemicrania, hemicrania continua
- Other primary headaches: cough headaches, headaches due to physical exertion, postcoital headache
Secondary headache
-
Bleeding
- Epidural hemorrhage
- Subdural hemorrhage
- Subarachnoid hemorrhage
- Intracerebral hemorrhage
- Vascular
- Autoimmune
-
Drug/toxin-related
- Alcohol use
- Alcohol withdrawal
- Food additives (e.g., MSG)
- Sympathomimetics (e.g., nicotine)
- Medication overuse headache
- Caffeine withdrawal
- Opioid withdrawal
- Nitroglycerin
- Carbon monoxide poisoning
-
Infectious
- Intracranial infections
- Meningitis
- Encephalitis
- Brain abscess
- Subdural empyema
- Aseptic meningitis
- Toxoplasmosis
- Systemic infections (e.g., influenza)
- Intracranial infections
-
Other
- Increased intracranial pressure
- Decreased intracranial pressure (e.g., post-lumbar puncture headache)
- Hydrocephalus
- Glaucoma
- Brain tumors
- Trigeminal neuralgia
- Hypoxia and/or hypercapnia (e.g., high-altitude headache)
- Hypertension
- Hypoglycemia
- Hypothyroidism
- Iridocyclitis
- Refractive errors
- Rhinosinusitis
- Postictal headache
- Cervicogenic headache (e.g., cervical disc disease)
- Temporomandibular joint disorders
- Postherpetic neuralgia
- Optic neuritis
- Psychiatric
The differential diagnoses listed here are not exhaustive.