Textbook of Urgent Care Medicine, Chapter 2, Headache

Published on October 26, 2026

Original authors: Michele Melamed and Raul Rodon

Originally published in 2014. Substantially updated and clinically reviewed in 2026 to reflect current evidence, guidelines, and urgent care practice.

Introduction

The International Headache Society has divided the etiologies of headaches into two groups: primary and secondary.

Most often, the headache that patients present with is of the primary type, which includes migraines, cluster headaches, and tension-type headaches.

The urgent care task is to recognize when a familiar primary headache pattern can be treated safely and when a secondary cause requires immediate emergency evaluation. Secondary headaches may result from hemorrhage, infection, vascular disease, glaucoma, pregnancy-related disease, toxic exposure, intracranial pressure disorders, or other serious pathology.

Table 1. Major Categories of Headache Disorders

Category	Common examples
Primary headache	Migraine with or without aura; tension-type headache; cluster headache and other trigeminal autonomic cephalalgias
Secondary headache	Head trauma; subarachnoid or other intracranial hemorrhage; meningitis/encephalitis; cervical artery dissection; cerebral venous thrombosis; giant cell arteritis; acute angle-closure glaucoma; carbon monoxide poisoning; medication/substance-related headache; pregnancy/postpartum disorders; intracranial mass or pressure disorder

Presentation

• Location: unilateral, bilateral, orbital, temporal, occipital, facial, or diffuse
• Quality: pulsating, pressure-like, tightening, stabbing, burning, or explosive
• Onset: gradual, sudden, or thunderclap; new versus recurrent; first or worst headache
• Associated symptoms: nausea, vomiting, photophobia, phonophobia, aura, autonomic symptoms, fever, neck stiffness, eye pain, visual change, focal neurologic symptoms, syncope, or altered mental status
• Triggers or context: exertion, cough/Valsalva, sexual activity, posture, trauma, pregnancy/postpartum state, medication change, dehydration, infection, or toxic exposure

Triage Pearls

The urgent care center’s support staff should watch for red flags and alert the clinician to them immediately:

• Thunderclap headache or headache reaching maximal intensity within seconds to minutes
• New focal neurologic deficit, seizure, altered level of consciousness, severe gait abnormality, or persistent confusion
• Fever with neck stiffness, petechial/purpuric rash, or toxic appearance
• Acute painful red eye, fixed or mid-dilated pupil, or sudden visual loss
• New severe headache during pregnancy or postpartum, particularly with hypertension, visual symptoms, neurologic symptoms, or seizure
• New headache after age 50 years, especially with jaw claudication, scalp tenderness, visual symptoms, or polymyalgia symptoms
• Headache after significant trauma or in a patient taking anticoagulants
• New severe headache with neck pain or partial Horner syndrome suggesting cervical artery dissection

History Pearls

Important headache parameters to assess include:

• Severity
• Onset
• Quality of pain
• Associated symptoms

Categories of medical history to consider:

• Prior history of headache
• Immunocompromise, including human immunodeficiency virus (HIV) infection
• Coagulopathy

• Trauma: possibility of subdural hematoma or post-traumatic headache syndrome
• Toxin exposure: look for carbon monoxide exposure, especially when more than one person in the same environment has headache or flu-like symptoms.
• Ask whether the present headache is similar to prior headaches or is a new pattern, more severe, more sudden, more frequent, or associated with a new neurologic symptom.
• Ask about pregnancy or postpartum status, oral contraceptives or estrogen exposure, malignancy, thrombophilia, recent infection, dehydration, and recent procedures when cerebral venous thrombosis is a concern.
• Ask about neck trauma or manipulation, abrupt neck movement, and associated Horner syndrome, diplopia, vertigo, dysarthria, or focal neurologic symptoms when cervical artery dissection is possible.
• Review acute and chronic headache medication use. Frequent use of combination analgesics, opioids, triptans, or simple analgesics can contribute to medication-overuse headache.

Table 2. Danger Signals in Headache

Danger signal	Urgent care concern
Thunderclap / first or worst headache	Subarachnoid hemorrhage, reversible cerebral vasoconstriction syndrome, dissection, cerebral venous thrombosis
Fever, meningismus, rash, toxic appearance	Meningitis, encephalitis, systemic infection
Focal neurologic deficit, seizure, confusion	Stroke, hemorrhage, mass lesion, infection, hypertensive emergency
Pregnancy or postpartum with new/severe headache	Preeclampsia/eclampsia, cerebral venous thrombosis, posterior reversible encephalopathy syndrome
Age >50 with new headache	Giant cell arteritis, mass lesion, glaucoma, vascular disease
Painful red eye / visual loss	Acute angle-closure glaucoma, optic or vascular emergency
Headache with neck pain or Horner syndrome	Carotid or vertebral artery dissection

Physical Exam Pearls

• Always take into consideration the first impression made by the patient. Is there evidence of toxicity, stress, or diaphoresis?
• Vital signs: blood pressure and temperature are key indicators of pathology.
• Head: palpate the scalp and look for pericranial muscle tenderness.
• If temporal arteritis is present, there may be induration or tenderness of the temporal artery.
• Eyes: inspect the eyelids, sclera, corneas, eye movements, pupils, and retinas.
• A painful red eye with a cloudy cornea, mid-dilated poorly reactive pupil, or visual loss should be treated as an ocular emergency.
• Perform a focused neurologic examination including mental status, cranial nerves, visual fields when feasible, motor and sensory function, coordination, and gait.
• Examine for meningismus when infection or subarachnoid hemorrhage is possible. Kernig, Brudzinski, and jolt tests do not reliably exclude meningitis when negative.
• Look for papilledema when the examination and equipment permit; suspected papilledema or raised intracranial pressure requires higher-level evaluation.
• In patients older than 50 years with a new headache, ask about jaw claudication and visual symptoms and examine the temporal arteries.

Testing Pearls

Testing should be directed by the history, examination, and red flags. Routine neuroimaging is not indicated for a typical recurrent primary headache with a normal neurologic examination and no red flags.

• Thunderclap headache: transfer for emergency evaluation. In an appropriate emergency-department setting, a normal noncontrast head CT performed within 6 hours of symptom onset in a patient with a normal neurologic examination can rule out nontraumatic subarachnoid hemorrhage when technical and interpretive conditions are met.
• If the patient remains at risk for subarachnoid hemorrhage after a negative noncontrast CT, further evaluation with lumbar puncture or CT angiography is appropriate; this workup generally belongs in the emergency department.
• Headache with neurologic deficit, cancer, immunocompromise, age >50 with new onset, post-traumatic onset, pregnancy/peripartum change, or features of intracranial pressure disorder warrants imaging selected for the suspected diagnosis.
• When giant cell arteritis is suspected, obtain erythrocyte sedimentation rate, C-reactive protein, and a complete blood count with platelet count when available; normal inflammatory markers do not absolutely exclude the disease.
• For suspected carbon monoxide poisoning, measure carboxyhemoglobin when available and begin high-concentration oxygen; standard pulse oximetry can appear normal.
• For pregnancy/postpartum headache, blood pressure and evaluation for preeclampsia should be performed promptly. Concerning presentations require emergency or obstetric evaluation rather than an extended urgent care workup.

Diagnosis Pearls

Migraines

• Migraine without aura typically lasts 4 to 72 hours when untreated and is associated with at least two of the following: unilateral location, pulsating quality, moderate to severe intensity, or aggravation by routine physical activity.
• Nausea/vomiting or both photophobia and phonophobia commonly accompany migraine.
• Migraine aura consists of fully reversible visual, sensory, speech/language, motor, brainstem, or retinal symptoms. Typical aura develops gradually, and each individual symptom usually lasts 5 to 60 minutes.
• A first aura after age 40, an exclusively negative neurologic symptom, very abrupt onset, prolonged symptoms, or an atypical pattern should prompt consideration of TIA, stroke, seizure, or another secondary cause.

Tension-Type Headaches

• Tension-type headaches are commonly bilateral, pressing or tightening, mild to moderate in intensity, and not aggravated by routine physical activity.
• Nausea and vomiting are absent; photophobia or phonophobia may occur, but typically not both.

Cluster Headaches

• Cluster headache produces severe or very severe unilateral orbital, supraorbital, or temporal pain lasting 15 to 180 minutes.
• Attacks are accompanied by ipsilateral autonomic findings such as conjunctival injection, lacrimation, nasal congestion, rhinorrhea, eyelid edema, ptosis, or miosis, and/or by marked restlessness or agitation.
• A new Horner syndrome, persistent neurologic abnormality, or atypical pattern requires evaluation for a secondary cause rather than an assumption of cluster headache.

Table 3. High-Risk Secondary Headaches

Condition	Urgent care clues
Subarachnoid hemorrhage	Thunderclap onset, exertional onset, vomiting, meningismus, syncope, or neurologic deficit. A normal neurologic exam does not exclude it.
Cervical artery dissection	Headache or neck pain, sometimes followed by focal neurologic symptoms; partial Horner syndrome may occur with carotid dissection.
Cerebral venous thrombosis	New headache with pregnancy/postpartum state, thrombophilia, estrogen exposure, malignancy, infection, seizure, papilledema, or focal deficit.
Giant cell arteritis	New headache after age 50, scalp tenderness, jaw claudication, visual symptoms, polymyalgia symptoms, or abnormal inflammatory markers.
Meningitis/encephalitis	Fever, altered mental status, neck stiffness, seizure, rash, or immunocompromise. Do not rely on negative meningeal signs to exclude disease.
Acute angle-closure glaucoma	Severe headache/eye pain, red eye, halos, nausea/vomiting, decreased vision, mid-dilated poorly reactive pupil.
Carbon monoxide poisoning	Headache, dizziness, nausea, confusion, chest symptoms, exposure history, or multiple patients from the same environment.

Treatment Pearls

Migraines

• For a typical mild to moderate migraine without red flags, early treatment with acetaminophen or an NSAID is reasonable when there is no contraindication.
• A triptan can be used for a patient with a known migraine pattern when there are no vascular contraindications; avoid using a triptan to treat a new focal neurologic syndrome until a secondary cause has been excluded.
• For moderate to severe migraine requiring parenteral treatment, useful urgent care options include metoclopramide or prochlorperazine when available and appropriate, with ketorolac as another option. Monitor for sedation, akathisia, dystonia, and QT-related risk when relevant.
• The 2025 American Headache Society emergency-department guideline gives its strongest recommendation to IV prochlorperazine and to greater occipital nerve block when appropriate expertise is available. These recommendations may be adapted to urgent care capabilities.
• Avoid routine opioid treatment for migraine. Hydromorphone specifically carries a strong recommendation against routine use in the 2025 AHS emergency guideline.
• Dexamethasone may reduce early migraine recurrence in selected patients but is not a primary analgesic.

Cluster Headaches

• The onset of most cluster headaches is abrupt, and treatment should be initiated rapidly too.
• Give 100% oxygen at a flow of at least 12 L/min by non-rebreather mask for approximately 15 minutes when available.
• Sumatriptan 6 mg subcutaneously is a first-line abortive treatment when not contraindicated.

Giant Cell Arteritis

• Because of the risk of irreversible vision loss, treatment should not be delayed when giant cell arteritis is strongly suspected.
• Visual symptoms, diplopia, or other evidence of cranial ischemia warrant emergency evaluation. In patients without visual ischemia, begin high-dose glucocorticoid therapy in coordination with prompt specialty follow-up when the diagnosis is strongly suspected.
• Temporal artery biopsy and/or vascular imaging is used to confirm the diagnosis; biopsy can remain informative after glucocorticoids have been started.

Other Emergencies

• Suspected meningitis, subarachnoid hemorrhage, cerebral venous thrombosis, cervical artery dissection, acute angle-closure glaucoma, severe carbon monoxide poisoning, hypertensive emergency, or pregnancy-related neurologic emergency requires transfer for definitive evaluation and treatment.
• For suspected carbon monoxide poisoning, remove the patient from exposure, administer 100% oxygen, and transfer for further evaluation; pregnancy, neurologic impairment, cardiac injury, severe acidosis, loss of consciousness, or high carboxyhemoglobin levels increase concern for hyperbaric therapy.

Disposition Pearls

Table 4. Urgent Care Disposition

Disposition	Criteria
Emergency department / EMS	Thunderclap headache; new focal deficit; seizure; altered mental status; meningismus/toxic appearance; suspected SAH, stroke, dissection, CVT, meningitis, glaucoma, CO poisoning, hypertensive emergency, or pregnancy-related emergency; severe visual symptoms; unstable vital signs.
Same-day specialty / ED depending on symptoms	Suspected giant cell arteritis without current visual loss; persistent new ocular or neurologic symptoms; atypical new headache needing advanced imaging; refractory vomiting or dehydration.
Urgent care treatment with outpatient follow-up	Typical primary headache pattern, normal neurologic examination, no red flags, symptoms improve with treatment, and reliable follow-up is available.

Medicolegal Pearls

• Document a complete medical history in the patient presenting with a headache.
• Activity at onset
• Time of onset
• Location of the headache
• Associated signs and symptoms
• Whether the patient describes the headache as the worst of their life
• It is crucial to note whether the patient describes a thunderclap onset to the headache.
• Document the neurologic examination, gait when appropriate, eye findings, and the presence or absence of red flags.
• Do not document “meningitis ruled out” solely because Kernig, Brudzinski, or jolt testing is negative.
• For suspected subarachnoid hemorrhage, document exact onset time, whether maximal intensity was immediate, neurologic findings, imaging timing when known, and the reason for ED transfer or additional testing.
• In patients older than 50 with new headache, document assessment for giant cell arteritis symptoms, particularly visual symptoms and jaw claudication.

References

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