Migraine in adults: diagnosis, acute treatment and prevention

Clinical scope and immediate priorities

Migraine is a common primary headache disorder diagnosed clinically from recurrent stereotyped attacks, associated symptoms and a normal or expected neurological examination between episodes. The safety-critical task is to identify when a new or changed headache requires investigation for secondary disease rather than assuming that all headache in a person with migraine is benign. Neurological assessment depends on chronology, focality, level of consciousness and careful exclusion of mimics. Time-sensitive disorders require parallel diagnostic and treatment pathways because waiting for every result can cause avoidable harm. Functional baseline, swallowing, cognition, mobility and medication effects also influence disposition and follow-up.

Recognition and differential diagnosis

Typical migraine is moderate to severe, often pulsatile, worsened by activity and associated with nausea and/or light and sound sensitivity. Aura causes reversible focal neurological symptoms that usually evolve over minutes. Sudden maximal-onset headache, new focal deficit, fever, papilloedema, pregnancy-associated severe headache, cancer or immunosuppression require a different pathway. The practical aim is to identify features that change urgency, distinguish common mimics and avoid anchoring on a single test result. Where the presentation is atypical, reassess the working diagnosis rather than forcing the findings to fit it.

Assessment and investigations

A careful history should document frequency, duration, associated symptoms, aura features, menstrual relationship, triggers and acute medication use. Routine neuroimaging is not indicated for a stable typical migraine pattern with normal examination, but imaging is appropriate when red flags, an atypical aura or meaningful change is present. A headache diary can quantify disability and medication exposure. Investigations should be sequenced so that urgent bedside information is obtained first, followed by tests that refine cause, severity or treatment choice. Trends, prior results and treatment effects often matter more than whether one value sits just inside or outside a reference range.

Initial and definitive management

Acute treatment commonly combines a triptan with an NSAID or paracetamol/acetaminophen where safe, with antiemetic therapy when needed. Newer gepants and other options may be available according to jurisdiction. Preventive treatment is considered when attacks are frequent, disabling, prolonged or poorly controlled, with choice among oral medicines, CGRP-targeted therapy and botulinum toxin guided by phenotype, comorbidity, access and local criteria. Treatment should address reversible causes and immediate physiological risk while preserving options for definitive care. Medication selection requires attention to allergies, interactions, renal or hepatic function, pregnancy where relevant, and the possibility that a medicine suitable in one health system may not be first-line in another.

Escalation, complications and special situations

Status migrainosus, dehydration, neurological features outside the usual aura pattern or concern for secondary headache requires urgent reassessment. Avoid opioids as routine migraine therapy. Medication overuse can perpetuate chronic headache and should be addressed explicitly. Escalate early when instability, organ dysfunction, rapidly progressive symptoms or a high-risk comorbidity is present. Frailty, pregnancy, immunosuppression, extremes of age and major renal or hepatic impairment can alter both presentation and treatment tolerance, so protocol-based care still requires individualisation.

International practice across English-speaking health systems

Across the United Kingdom, United States, Canada, Australia, New Zealand and Ireland, the core clinical principles are broadly similar, but drug licensing, formularies, emergency pathways, screening thresholds, referral criteria and professional scope can differ. Use the most recent national or regional guidance, local antimicrobial or medicines policy, and the relevant product information when an operational detail could change treatment. MDPDA therefore presents a common evidence-based framework and highlights areas that should be adapted locally rather than implying that one country’s pathway is universal.

Monitoring, follow-up and prevention

Follow-up should be purposeful rather than routine. Define what is being monitored, when it should be reassessed and what finding would change management. Review adherence and adverse effects, repeat objective measurements when they inform risk, and reconsider the diagnosis if the clinical course is inconsistent with expectations. Safety-netting should state which symptoms require urgent reassessment and which service should be contacted. For chronic disease, prevention, vaccination where relevant, smoking cessation, nutrition, physical activity and management of related cardiovascular or metabolic risk can be as important as disease-specific treatment. Judge prevention by reduction in frequency and disability after an adequate trial, not by expecting complete abolition of headache. Reassess the need for ongoing prevention periodically and address sleep, exercise, stress and trigger management without implying that lifestyle alone causes migraine.

Common pitfalls and safety checks

Do not image every patient with typical stable migraine. Do not assume a new thunderclap headache is migraine because the patient has a migraine history. Frequent use of acute medicines can worsen headache through medication overuse. Opioids are generally poor routine migraine treatments. A useful final check is to ask what dangerous alternative diagnosis could still explain the presentation, whether the patient has demonstrated an appropriate response to treatment, and whether the discharge or transfer plan is safe if symptoms recur.

Documentation, communication and shared decisions

Documentation should make the clinical reasoning visible. Record the key positive and negative findings, relevant risk stratification, important investigations, treatment rationale, discussions with the patient or family where appropriate, and the trigger for escalation or review. When care crosses settings, handover should identify unresolved diagnostic questions, medicines started or withheld, pending results and who is responsible for follow-up. Shared decisions are particularly important when more than one reasonable strategy exists or when treatment benefit must be balanced against bleeding, frailty, treatment burden or quality of life.

Implementation across care settings

Neurological safety depends heavily on transitions of care. Record the patient’s pre-event function, cognition, swallowing, driving or occupational implications and whether family or carers have observed features not seen in clinic. Time-critical imaging and treatment pathways vary in organisation, but delays should be measured and reviewed. Before discharge, make explicit which recurrent symptoms are emergencies, what medicine changes have been made and which team owns follow-up. Rehabilitation needs should be identified alongside disease-specific treatment because mobility, speech and cognition frequently determine outcome.

Quality and patient-safety review

Before closing the episode of care, confirm that the working diagnosis remains consistent with the observed course, that high-risk alternatives have been considered, and that treatment has not introduced a new avoidable hazard. Review allergies, interactions, renal or hepatic constraints, pregnancy considerations where relevant, and the patient’s ability to follow the plan. The safest pathway is one in which the next clinician can understand what has been decided, what remains uncertain and which finding should trigger escalation.

Applying evidence to the individual patient

Guidelines provide a framework, but safe implementation depends on the patient’s baseline function, comorbidities, concurrent medicines, treatment goals and access to follow-up. Recommendations should be interpreted in light of absolute rather than relative benefit where possible, and clinicians should identify when the evidence base under-represents older people, pregnancy, severe kidney or liver impairment, multimorbidity or other groups. When two reasonable options exist, explain the trade-offs and document the reason for the selected approach. If local policy differs from an international recommendation, determine whether this reflects formulary, service configuration, licensing or genuinely different evidence. Reassessment is part of evidence-based care: a working diagnosis or treatment plan that no longer fits the clinical course should be revised rather than defended simply because it matched the initial pathway.

Practical review checklist

Before finalising management, confirm that the severity has been classified correctly, essential investigations have been acted on, and any test still pending has a named clinician or service responsible for review. Reconcile regular medicines and temporary changes, check whether monitoring is required after initiation or dose adjustment, and make the follow-up interval proportionate to risk. Explain the plan in language the patient can use, including what improvement is expected, which adverse effects matter and which symptoms require urgent help. Where care is shared between primary, secondary, dental, pharmacy or community services, avoid ambiguous instructions such as ‘follow up as needed’; specify who should do what and when. This final systems check often prevents harm that is not caused by the clinical decision itself but by gaps in implementation.