Approach to Headache in Adults
Initial Classification: Primary vs Secondary Headache
Begin by determining whether the headache is primary (migraine, tension-type, cluster) or secondary (underlying pathology), using red flag screening to identify life-threatening causes that require immediate imaging and intervention. 1
Red Flag Assessment (Requires Urgent Evaluation)
Screen for these features that mandate emergency workup:
- Thunderclap onset ("worst headache of life") suggests subarachnoid hemorrhage 1
- New-onset headache after age 50 raises concern for giant cell arteritis, tumor, or stroke 1, 2
- Progressive worsening over days to weeks suggests space-occupying lesion 1
- Awakens patient from sleep or worsens with Valsalva/cough indicates increased intracranial pressure 3, 1
- Focal neurological deficits (weakness, numbness, vision loss, ataxia) 1
- Fever with neck stiffness suggests meningitis 1
- Recent head/neck trauma 1
- Altered consciousness, memory, or personality changes 1
If any red flag is present, obtain immediate neuroimaging and consider emergency admission. 1
Detailed History Taking
Temporal Pattern
- Age at onset: Migraine typically begins at/around puberty; new-onset after age 50 requires investigation for secondary causes 1, 4
- Duration of episodes: Migraine lasts 4-72 hours; cluster headache 15-180 minutes; tension-type is variable 1
- Frequency: Document if episodic vs ≥15 days/month (suggests chronic migraine or medication-overuse headache) 1
- Time of day: Headaches awakening from sleep suggest secondary pathology 3, 1
- Menstrual cycle relationship in women 3
Pain Characteristics
- Location: Unilateral (migraine, cluster) vs bilateral (tension-type) 1
- Quality: Pulsating/throbbing (migraine) vs pressing/tightening (tension-type) vs severe unilateral (cluster) 3, 1
- Severity: Moderate-to-severe (migraine, cluster) vs mild-to-moderate (tension-type) 1
- Aggravating factors: Routine physical activity worsens migraine but not tension-type 1
Associated Symptoms
- Nausea/vomiting, photophobia, phonophobia point to migraine 1
- Ipsilateral autonomic symptoms (lacrimation, conjunctival injection, nasal congestion, ptosis) indicate cluster headache 1, 5
- Aura symptoms: Visual/hemisensory disturbances lasting 5-60 minutes before headache onset suggest migraine with aura 1
- Scalp tenderness and jaw claudication in patients >50 years suggest giant cell arteritis 1
Medication History (Critical for Medication-Overuse Headache)
- Document all acute medications: Non-opioid analgesics ≥15 days/month or other acute medications (triptans, ergots, combination analgesics) ≥10 days/month for >3 months defines medication-overuse headache 1
- Include over-the-counter medications and substances obtained from others 6
Physical and Neurological Examination
- Complete neurologic examination in all patients 6
- Head and neck examination: Palpate temporal arteries for tenderness (giant cell arteritis), assess neck stiffness 1
- Fundoscopic examination for papilledema (increased intracranial pressure) 1
If neurologic examination is abnormal or unexplained findings are present, neuroimaging is indicated. 3
Diagnostic Tools
Screening Questionnaires
- ID-Migraine (3-item): Sensitivity 81%, specificity 75%, positive predictive value 93% 1
- Migraine Screen Questionnaire (5-item): Sensitivity 93%, specificity 81% 1
Headache Diary
Implement a headache diary to document frequency, duration, character, triggers, accompanying symptoms, and medication use—this reduces recall bias and increases diagnostic accuracy. 1, 4
Neuroimaging Indications
When to Image
- MRI brain with and without contrast is preferred for subacute presentations, suspected tumor, or inflammatory process (higher resolution, no radiation) 1
- Non-contrast CT head if presenting <6 hours from acute severe headache onset (subarachnoid hemorrhage detection: 95% sensitivity day 0,74% day 3,50% at 1 week) 1
- CT head for acute trauma or abrupt-onset headache 1
When Imaging is NOT Warranted
In patients with normal neurologic examination and headache meeting strict criteria for primary headache disorder (migraine, tension-type), neuroimaging is usually not warranted. 3 The yield is extremely low: brain tumors 0.8%, arteriovenous malformations 0.2%, aneurysms 0.1% in patients with normal examination 2
Additional Laboratory Testing
- ESR/CRP if temporal arteritis suspected (patients >50 years with new-onset headache); note ESR can be normal in 10-36% of giant cell arteritis cases 1, 2
- Morning TSH and free T4 if cold intolerance or lightheadedness present 1
- Lumbar puncture with spectrophotometry if thunderclap headache with negative CT (xanthochromia detection: 100% at 12 hours to 2 weeks, >70% at 3 weeks) 2
Diagnosis of Common Primary Headaches
Migraine Without Aura
Requires at least 5 lifetime attacks with:
- Duration 4-72 hours 1
- At least 2 of: Unilateral, pulsating, moderate-to-severe intensity, aggravated by routine activity 1
- At least 1 of: Nausea/vomiting OR photophobia AND phonophobia 1
Tension-Type Headache
- Bilateral, mild-to-moderate pressing/tightening quality 1
- Lacks migraine features (no nausea, no photophobia/phonophobia) 1
- Not aggravated by routine activity 1
Cluster Headache
- Strictly unilateral severe headache lasting 15-180 minutes 1, 5
- Frequency 1-8 attacks daily 5
- At least one ipsilateral autonomic symptom (lacrimation, conjunctival injection, nasal congestion, ptosis, miosis) 1, 5
Chronic Migraine
- ≥15 headache days/month for >3 months, with ≥8 days meeting migraine criteria 1
Medication-Overuse Headache
- ≥15 headache days/month with regular overuse of non-opioid analgesics ≥15 days/month OR other acute medications ≥10 days/month for >3 months 1
Acute Treatment
Mild-to-Moderate Migraine
NSAIDs or acetaminophen are first-line for mild-to-moderate migraine attacks. 1 Administer as early as possible during an attack to improve efficacy 3
Moderate-to-Severe Migraine
Triptans (5-HT1B/D agonists) or ergot derivatives for moderate-to-severe migraine or when NSAIDs fail. 1 Triptans eliminate pain in 20-30% of patients by 2 hours but cause transient flushing, tightness, or tingling in 25% 7
Avoid triptans in patients with or at high risk for cardiovascular disease due to vasoconstrictive properties. 7 Screen for CAD risk factors (hypertension, hypercholesterolemia, smoking, obesity, diabetes, family history) before prescribing 5
Alternative Acute Treatments
- Gepants (rimegepant, ubrogepant): Eliminate headache in 20% at 2 hours; adverse effects include nausea and dry mouth in 1-4% 7
- Lasmiditan (5-HT1F agonist): Safe in patients with cardiovascular risk factors 7
- Antiemetics for nausea/vomiting 1
Cluster Headache Acute Treatment
High-flow oxygen (100% at 12-15 L/min) is first-line acute treatment for cluster headache. 1, 5 Subcutaneous sumatriptan 6 mg provides relief in 70% within 10 minutes 5
Preventive Therapy
Consider preventive therapy if patient has >2 headaches per week. 3
Migraine Prevention
- Antihypertensives, antiepileptics (topiramate), antidepressants, calcitonin gene-related peptide monoclonal antibodies, onabotulinumtoxinA reduce migraine by 1-3 days per month relative to placebo 7
Cluster Headache Prevention
Verapamil is the prophylactic drug of choice, starting at 360 mg/day, with ECG monitoring for PR interval prolongation at higher doses. 5 Consider oral corticosteroids or greater occipital nerve blockade as bridging therapy 5
Medication-Overuse Headache Management
Patients overusing opiates, barbiturates, or benzodiazepines require slow tapering and possibly inpatient treatment to prevent acute withdrawal. 6 Patients overusing other agents can usually withdraw more quickly 6
Referral Criteria
- Emergency admission: Any red flag present, patient unable to self-care without help 1
- Urgent neurology referral (within 48 hours): Suspected spontaneous intracranial hypotension 1
- Routine neurology referral (2-4 weeks): Suspected primary headache disorder, diagnosis uncertain, first-line treatments fail 1
- Rheumatology referral: Suspected giant cell arteritis 1
Common Pitfalls
- Failing to screen for medication overuse: Always document frequency of all acute medication use, including over-the-counter analgesics 1, 6
- Over-imaging low-risk patients: Neuroimaging yield is <1% for most pathologies in patients with normal examination and typical primary headache features 2
- Missing giant cell arteritis: ESR can be normal in 10-36% of cases; maintain high clinical suspicion in patients >50 years with new-onset headache 1, 2
- Prescribing triptans without cardiovascular screening: Always assess CAD risk factors before initiating triptan therapy 5, 7
- Inadequate acute treatment dosing: Administer adequate first dose early in attack; under-dosing leads to treatment failure and medication overuse 3