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:
Trigeminal autonomic cephalgias (including cluster headache, chronic paroxysmal hemicrania, hemicrania continua, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing [SUNCT])
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
Cause | Examples |
|---|---|
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) Vascular disorders (eg, ischemic stroke, hemorrhagic stroke, vascular malformations, vasculitis, venous sinus thrombosis) Cerebral venous sinus thrombosis |
Systemic disorders | Acute severe hypertension Hypoxia (including altitude sickness) Viral infections Viremia |
Medications,/other substances, and toxins | Analgesic overuse Hormone therapy (eg, estrogen) Nitrates Proton pump inhibitors |
Some Characteristics of Headache Disorders by Cause
Cause | Suggestive Findings | Diagnostic Approach* |
|---|---|---|
Primary headache disorders† | ||
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 examination alone | |
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 examination alone | |
Frequent or continuous, mild, bilateral, and viselike occipital or frontal pain that spreads to entire head Worse at end of day | Clinical examination alone | |
Secondary headache | ||
Unilateral frontal or orbital Halos around lights, decreased visual acuity, conjunctival injection, vomiting | Tonometry | |
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 examination alone | |
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) | Carboxyhemoglobin level |
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 examination alone |
Dental infections (in upper teeth) | Pain usually felt over the face, mostly unilateral, and worsened by chewing. Toothache | Dental examination |
Fever, altered mental status, seizures, focal neurologic deficits | MRI, CSF analysis | |
Age > 50 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 | Clinical evaluation |
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 | |
Sudden onset Vomiting, focal neurologic deficits, altered mental status | Neuroimaging | |
Chronic headache (usually chronic migraine) 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 examination alone | |
Fever, meningismus, altered mental status | CSF analysis, often preceded by CT | |
Postcoital headache | Headache after orgasm | Clinical examination alone |
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 or tension-type headache with neck pain | Clinical examination alone |
Positional facial or tooth pain, fever, purulent rhinorrhea | Clinical evaluation, sometimes CT | |
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 | Neuroimaging |
Trigeminal neuralgia | Repeated short, lancinating severe pain on one side of the lower face | Clinical examination alone |
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 | Neuroimaging |
* Clinical examination is always done but is mentioned in this column only when that can be the sole means of diagnosis. | ||
† 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 underlying disorder
If no cause or serious symptoms are identified, evaluation focuses on diagnosing primary headache disorders.
History
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. Patients are asked whether headaches occur only when standing; such headaches are a concern because they may be caused by a cerebrospinal fluid (CSF) leak or postural orthostatic tachycardia syndrome (POTS). 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
Vomiting: Migraine or increased intracranial pressure
Fever: Infection (eg, encephalitis, meningitis, sinusitis)
Red eye and/or visual symptoms (halos, blurring): Acute angle-closure glaucoma
Visual field deficits, diplopia, or blurring vision: Ocular migraine, brain mass lesion, or idiopathic intracranial hypertension
Lacrimation and facial flushing: Cluster headache
Rhinorrhea: Sinusitis
Pulsatile tinnitus: Idiopathic intracranial hypertension
Preceding aura: Migraine
Focal neurologic deficit: Encephalitis, meningitis, intracerebral hemorrhage, subdural hematoma, tumor, or other mass lesion
Seizures: Encephalitis, tumor, or other mass lesion
Syncope at headache onset: Subarachnoid hemorrhage
Myalgias and/or vision changes (in people> 50 years): Giant cell arteritis
Past medical historyDisorders Causing Secondary Headache
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 | Causes |
|---|---|
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 |
Meningismus | 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) | Cancer, HIV, AIDS |
Progressively worsening headache | Secondary headache |
Red eye and halos around lights |
Testing
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.
MRI (and perhaps magnetic resonance angiography [MRA]) should be done as soon as possible in patients with any of the following findings:
Thunderclap headache
Altered mental status
Meningismus
Acute focal neurologic deficit
If MRI is not immediately available, CT can be used.
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
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 imaging and examination findings are normal as long as lumbar puncture is not contraindicated by imaging results. CSF analysis is also usually indicated if patients with headache are immunosuppressed or if they have papilledema.
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) and C-reactive protein (CRP) 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: Headache
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 after neuroimaging for patients with meningismus and usually for immunosuppressed patients and those with papilledema.
Patients with thunderclap headache require CSF analysis even if neuroimaging and examination findings are normal as long as lumbar puncture is not contraindicated by imaging results.
