A patient sits down and tells you they have headaches. They've probably already been told — by a GP, a neurologist, sometimes just a well-meaning relative — that they have migraines. They may have tried triptans. They may have carried a diagnosis for a decade. Your job, before you touch the cervical spine, is to decide whether that label actually fits. Or whether something mechanically specific is being missed by everyone who saw them first.
Cervicogenic headache and migraine share enough surface features to make differentiation genuinely hard. Both can be unilateral. Both can be severe enough to destroy a working week. Both can present with nausea, photophobia, and a strong pull toward a dark room and a horizontal surface. The overlap is not trivial — and the research reflects it. Population studies consistently show cervicogenic headache is underdiagnosed, partly because migraine has become the default explanatory framework for recurrent head pain in primary care. For chiropractors seeing this patient group, that underdiagnosis is both a clinical problem and a reason to take the musculoskeletal assessment seriously.
The distinctions that matter most are mechanical and historical.
Cervicogenic headache, as described by the IHS diagnostic criteria, originates in the cervical spine and is referred to the head. It is typically unilateral without side-shift, and reproducible by sustained neck postures or specific cervical movements. Pressure over the upper cervical segments — particularly C1 to C3 — often reproduces or modifies the patient's familiar pain. It does not meet the criteria for migraine, though it may coexist with migraine, which is where the picture becomes genuinely complicated. A patient can have both. Treating only the cervicogenic component will not resolve the migrainous episodes, and assuming it will is a clinical error that takes several follow-up appointments to recognise.
A careful history is where differentiation begins. Not just the character of the pain — its relationship to posture, sustained activity, and neck position. A desk worker whose headaches reliably develop after two hours at a screen and ease with movement is telling a different story than someone whose headaches arrive with prodromal visual disturbance and worsen with any physical activity whatsoever. The Cervicogenic Headache International Study Group criteria and the ICHD-3 classification offer a useful framework for structuring that thinking, even when clinical reality refuses to present in clean diagnostic categories. It rarely does.
Physical examination should include a methodical assessment of the upper cervical spine: range of motion, segmental mobility testing, palpation of the suboccipital musculature and C1-C3 facet joints. The flexion-rotation test — which has reasonable supporting evidence for identifying C1-C2 dysfunction in cervicogenic headache — is worth incorporating as a structured part of the assessment. Restricted and painful ipsilateral rotation to the side of the headache is a meaningful clinical finding. It is not pathognomonic. No single test closes the diagnostic question, and anyone who tells you otherwise is selling a course.
Where chiropractors add genuine value is in this layered, time-invested assessment. Taking a headache presentation seriously as a mechanical problem rather than defaulting to a neurological label and referring on. That does not mean ignoring red flags — any headache with features suggesting raised intracranial pressure, vascular origin, or a pattern that simply does not fit a musculoskeletal model warrants prompt investigation and onward referral. Headache management sits precisely at the boundary where professional judgement matters most, and that boundary deserves respect in both directions.
The clinical skill here is not in choosing between two competing diagnoses. It is in recognising that the question itself may be insufficiently precise. Cervicogenic headache and migraine can coexist, can mask each other, and can be maintained by different mechanisms in the same patient at the same time. A thorough upper cervical examination, a history that takes the patient's account of their own pain seriously — when it started, what makes it better, what the pattern looks like over weeks not just hours — and a willingness to sit with diagnostic uncertainty long enough to build an accurate picture: these are the tools that distinguish considered practice from reflexive pattern-matching.
The patient who has carried a migraine label for ten years and responds well to upper cervical treatment is not a surprise. They are the predictable outcome of a careful assessment that most previous clinicians did not have the training, the time, or the clinical framework to perform. That assessment is what you have. Use it before reaching for any other explanation.