Skip to Content

Approach to the Patient With Headache


Stephen D. Silberstein

, MD, Sidney Kimmel Medical College at Thomas Jefferson University

Last full review/revision Apr 2020| Content last modified Apr 2020

Headache is pain in any part of the head, including the scalp, face (including the orbitotemporal area), and interior of the head. Headache is one of the most common reasons patients seek medical attention.

Pathophysiology of Headache

Headache is due to activation of pain-sensitive structures in or around the brain, skull, face, sinuses, or teeth.

Etiology of Headache

Headache may occur as a primary disorder or be secondary to another disorder.

Primary headache disorders include the following:

  • Migraine
  • Trigeminal autonomic cephalgias (including cluster headache, chronic paroxysmal hemicrania, hemicrania continua, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing)
  • Tension-type headache

Secondary headache has numerous causes (see table Disorders Causing Secondary Headache).

Overall, the most common causes of headache are

  • Tension-type headache
  • Migraine

Some causes of headache are common; others are important to recognize because they are dangerous, require specific treatment, or both (see table Some Characteristics of Headache Disorders by Cause).

Disorders Causing Secondary Headache



Extracranial disorders

Carotid or vertebral artery dissection (which also causes neck pain)

Dental disorders (eg, infection, temporomandibular joint dysfunction)



Intracranial disorders

Brain tumors and other masses

Chiari type I malformation

Cerebrospinal fluid leak with low-pressure headache

Hemorrhage (intracerebral hemorrhage, subdural hemorrhage, subarachnoid hemorrhage)

Idiopathic intracranial hypertension

Infections (eg, abscess, encephalitis, meningitis, subdural empyema)

Meningitis, noninfectious (eg, carcinomatous, chemical)

Obstructive hydrocephalus

Vascular disorders (eg, ischemic stroke, hemorrhagic stroke, vascular malformations, vasculitis, venous sinus thrombosis)

Cerebral venous sinus thrombosis

Systemic disorders

Acute severe hypertension



Giant cell arteritis


Hypoxia (including altitude sickness)

Viral infections


Drugs and toxins

Analgesic overuse

Caffeine withdrawal

Carbon monoxide

Hormones (eg, estrogen)


Proton pump inhibitors

Some Characteristics of Headache Disorders by Cause


Suggestive Findings

Diagnostic Approach

Primary headache disorders*

Cluster headache

Multiple unilateral orbitotemporal attacks, often at the same time of day

Deep, severe, lasting 30–180 minutes

Often with lacrimation, rhinorrhea, facial flushing, or Horner syndrome; restlessness

Clinical evaluation

Migraine headache

Unilateral or bilateral and pulsating, lasting 4–72 hours

Occasionally with aura

Usually nausea, photophobia, sonophobia, or osmophobia

Worse with activity, preference to lie in the dark, resolution with sleep

Clinical evaluation

Tension-type headache

Frequent or continuous, mild, bilateral, and viselike occipital or frontal pain that spreads to entire head

Worse at end of day

Clinical evaluation

Secondary headache

Acute angle-closure glaucoma

Unilateral frontal or orbital

Halos around lights, decreased visual acuity, conjunctival injection, vomiting


Altitude sickness

Light-headedness, anorexia, nausea, vomiting, fatigue, irritability, difficulty sleeping

In patients who have recently gone to a high altitude (including flying ≥ 6 hours in an airplane)

Clinical evaluation

Carbon monoxide poisoning

Often exposure to incompletely combusted hydrocarbons (eg, house fires, improperly vented automobiles, gas heaters, furnaces, hot water heaters, wood- or charcoal-burning stoves, kerosene heaters)

A blood test

Cerebral venous sinus thrombosis

Symptoms similar to those of idiopathic intracranial hypertension but may begin suddenly

Neuroimaging (preferably MRI with magnetic resonance venography)

Cervicogenic headache

Pain in neck area

Clinical evaluation

Dental infections (in upper teeth)

Pain usually felt over the face, mostly unilateral, and worsened by chewing.


Dental examination


Fever, altered mental status, seizures, focal neurologic deficits

MRI, CSF analysis

Giant cell arteritis

Age > 55

Unilateral throbbing pain, pain when combing hair, visual disturbances, jaw claudication, fever, weight loss, sweats, temporal artery tenderness, proximal myalgias

ESR, temporal artery biopsy, usually neuroimaging

Hypertensive headache

Associated with sudden severe rise of BP


Idiopathic intracranial hypertension

Migraine-like headache, diplopia, pulsatile tinnitus, loss of peripheral vision, papilledema

Usually gradual onset

Neuroimaging (preferably MRI with magnetic resonance venography), followed by measurement of CSF opening pressure and cell count culture and analysis

Intracerebral hemorrhage

Sudden onset

Vomiting, focal neurologic deficits, altered mental status


Medication overuse headache

Chronic headache with variable location and intensity

Occurs frequently and can be daily

Often present on awakening

Typically develops after overuse of analgesics taken for an episodic headache disorder

Clinical evaluation


Fever, meningismus, altered mental status

CSF analysis, often preceded by CT

Postcoital headache

Headache after orgasm

Clinical evaluation

Post-lumbar puncture and other low-pressure headaches

Intense headaches, often with meningismus and/or vomiting

Worsened by sitting or standing and alleviated only by lying completely flat

For post-lumbar headache, clinical evaluation

For other low-pressure headaches (eg, CSF leaks), sometimes MRI with gadolinium

Posttraumatic headache (usually a migraine or tension-type headache)

Similar to migraine, tension-type headache, and neck pain

History of head or neck trauma


Positional facial or tooth pain, fever, purulent rhinorrhea

Clinical evaluation, sometimes CT

Subarachnoid hemorrhage

Peak intensity a few seconds after headache onset (thunderclap headache)

Vomiting, syncope, obtundation, meningismus

Neuroimaging, followed by CSF analysis if it is not contraindicated and imaging is not diagnostic

Subdural hematoma (chronic)

Sleepiness, altered mental status, hemiparesis, loss of spontaneous retinal venous pulsations, papilledema

Presence of risk factors (eg, older age, coagulopathy, dementia, anticoagulant use, ethanol abuse)


Trigeminal neuralgia

Repeated short, lancinating severe pain on one side of the lower face

Clinical evaluation

Tumor or mass

Eventually altered mental status, seizures, vomiting, diplopia when looking laterally, loss of spontaneous retinal venous pulsations or papilledema, focal neurologic deficits

Aggravated by recumbency; worse on awakening or awakens patient from sleep


*Primary headaches are usually recurrent.

BP = blood pressure; CSF = cerebrospinal fluid; ESR = erythrocyte sedimentation rate.

Evaluation of Headache

Evaluation of headache focuses on

  • Determining whether a secondary headache is present
  • Checking for symptoms that suggest a serious cause

If no cause or serious symptoms are identified, evaluation focuses on diagnosing primary headache disorders.


History of present illness includes questions about the headache's characteristics:

  • Location
  • Duration
  • Severity
  • Onset (eg, sudden, gradual)
  • Quality (eg, throbbing, constant, intermittent, pressure-like)

Exacerbating and remitting factors (eg, head position, time of day, sleep, light, sounds, physical activity, odors, chewing) are noted. If the patient has had previous or recurrent headaches, the previous diagnosis (if any) needs to be identified, and whether the current headache is similar or different needs to be determined. For recurrent headaches, the following are noted:

  • Age at onset
  • Frequency of episodes
  • Temporal pattern (including any relationship to phase of menstrual cycle)
  • Response to treatments (including over-the-counter treatments)

Review of systems should seek symptoms suggesting a cause, including

Past medical history should identify risk factors for headache, including exposure to drugs, substances (particularly caffeine), and toxins (see table Disorders Causing Secondary Headache); recent lumbar puncture; immunosuppressive disorders or IV drug use (risk of infection); hypertension (risk of brain hemorrhage); cancer (risk of brain metastases); and dementia, trauma, coagulopathy, or use of anticoagulants or ethanol (risk of subdural hematoma).

Family and social history should include any family history of headaches, particularly because migraine headache may be undiagnosed in family members.

To streamline data collection, clinicians can ask patients to fill out a headache questionnaire that covers most of the relevant medical history pertinent to diagnosis of headache. Patients may complete the questionnaire before their visit and bring the results with them.

Physical examination

Vital signs, including temperature, are measured. General appearance (eg, whether restless or calm in a dark room) is noted. A general examination, with a focus on the head and neck, and a full neurologic examination are done.

The scalp is examined for areas of swelling and tenderness. The ipsilateral temporal artery is palpated, and both temporomandibular joints are palpated for tenderness and crepitance while the patient opens and closes the jaw.

The eyes and periorbital area are inspected for lacrimation, flushing, and conjunctival injection. Pupillary size and light responses, extraocular movements, and visual fields are assessed. The fundi are checked for spontaneous retinal venous pulsations and papilledema. If patients have vision-related symptoms or eye abnormalities, visual acuity is measured. If the conjunctiva is red, the anterior chamber and cornea are examined with a slit lamp if possible, and intraocular pressure is measured.

The nares are inspected for purulence. The oropharynx is inspected for swellings, and the teeth are percussed for tenderness.

Neck is flexed to detect discomfort, stiffness, or both, indicating meningismus. The cervical spine is palpated for tenderness.

Red flags

The following findings are of particular concern:

  • Neurologic symptoms or signs (eg, altered mental status, weakness, diplopia, papilledema, focal neurologic deficits)
  • Severe hypertension
  • Immunosuppression or cancer
  • Meningismus
  • Onset of headache after age 50
  • Thunderclap headache (severe headache that peaks within a few seconds)
  • Symptoms of giant cell arteritis (eg, visual disturbances, jaw claudication, fever, weight loss, temporal artery tenderness, proximal myalgias)
  • Systemic symptoms (eg, fever, weight loss)
  • Progressively worsening headache
  • Red eye and halos around lights

Interpretation of findings

If similar headaches recur in patients who appear well and have a normal examination, the cause is rarely ominous. Headaches that have recurred since childhood or young adulthood suggest a primary headache disorder. If headache type or pattern clearly changes in patients with a known primary headache disorder, secondary headache should be considered.

Most single symptoms of primary headache disorders other than aura are nonspecific. A combination of symptoms and signs is more characteristic (see table Some Characteristics of Headache Disorders by Cause).

Red flag findings suggest a cause (see table Matching Red Flag Findings With a Cause for Headache).

Matching Red Flag Findings With a Cause for Headache

Suggestive Findings


Neurologic symptoms or signs (eg, altered mental status, confusion, neurogenic weakness, diplopia, papilledema, focal neurologic deficits)

Encephalitis, subdural hematoma, subarachnoid hemorrhage, cerebral venous sinus thrombosis, intracerebral hemorrhage, tumor, other intracranial mass, increased intracranial pressure

Immunosuppression or cancer

Central nervous system infection, metastases


Meningitis, subarachnoid hemorrhage, subdural empyema

Onset of headache after age 50

Increased risk of a serious cause (eg, tumor, giant cell arteritis)

Thunderclap headache (severe headache that peaks within a few seconds)

Subarachnoid hemorrhage

Combination of fever, weight loss, visual disturbances, jaw claudication, temporal artery tenderness, and proximal myalgias

Giant cell arteritis

Systemic symptoms (eg, fever, weight loss)

Sepsis, hyperthyroidism, cancer

Progressively worsening headache

Secondary headache

Red eye and halos around lights

Acute angle-closure glaucoma


Most patients can be diagnosed without testing. However, some serious disorders may require urgent or immediate testing. Some patients require tests as soon as possible.

CT (or MRI) should be done as soon as possible in patients with any of the following findings:

  • Thunderclap headache
  • Altered mental status
  • Meningismus
  • Papilledema
  • Signs of sepsis (eg, rash, shock)
  • Acute focal neurologic deficit
  • Severe hypertension (eg, systolic > 220 mm Hg or diastolic >120 mm Hg on consecutive readings)

Also, neuroimaging, usually MRI, should be done if patients have any of the following:

  • Focal neurologic deficit of subacute or uncertain onset
  • New onset
  • Age > 50 years
  • Weight loss
  • Cancer
  • HIV infection or AIDS
  • Change in an established headache pattern
  • Diplopia

In addition, if meningitis, subarachnoid hemorrhage, encephalitis, or any cause of meningismus is being considered, lumbar puncture and cerebrospinal fluid (CSF) analysis should be done, if not contraindicated by imaging results. Patients with a thunderclap headache require CSF analysis even if CT and examination findings are normal as long as lumbar puncture is not contraindicated by imaging results. CSF analysis is also indicated if patients with headache are immunosuppressed.

Tonometry should be done if findings suggest acute narrow-angle glaucoma (eg, visual halos, nausea, corneal edema, shallow anterior chamber).

Other testing should be done within hours or days, depending on the acuity and seriousness of findings and suspected causes.

Erythrocyte sedimentation rate (ESR) should be determined if patients have visual symptoms, jaw or tongue claudication, temporal artery signs, or other findings suggesting giant cell arteritis.

CT of the paranasal sinuses is done to rule out complicated sinusitis if patients have a moderately severe systemic illness (eg, high fever, dehydration, prostration, tachycardia) and findings suggesting sinusitis (eg, frontal, positional headache; epistaxis; purulent rhinorrhea).

Lumbar puncture and CSF analysis are done if headache is progressive and findings suggest idiopathic intracranial hypertension (eg, transient obscuration of vision, diplopia, pulsatile intracranial tinnitus) or chronic meningitis (eg, persistent low-grade fever, cranial neuropathies, cognitive impairment, lethargy, vomiting).

Treatment of Headache

Treatment of headache is directed at the cause.

Geriatrics Essentials

New-onset headache after age 50 should be considered a secondary disorder until proven otherwise.

Key Points

  • Recurrent headaches that began at a young age in patients with a normal examination are usually benign.
  • Neuroimaging is recommended as soon as possible for patients with altered mental status, seizures, papilledema, focal neurologic deficits, or thunderclap headache.
  • CSF analysis is required for patients with meningismus and usually for immunosuppressed patients after neuroimaging.
  • Patients with thunderclap headache require CSF analysis even if CT and examination findings are normal as long as lumbar puncture is not contraindicated by imaging results.

Copyright © 2021 Merck & Co., Inc., known as MSD outside of the US, Kenilworth, New Jersey, USA. All rights reserved. Merck Manual Disclaimer