Assume it is migraine unless proven otherwise.

Even though significant progress has been made in understanding migraine headache pathophysiology and bringing new therapeutic options into practice, migraine remains underdiagnosed and undertreated in the United States. This paper couples recent research and expert opinion to provide practical guidance on the diagnosis of migraine for the primary care setting, where many patients first seek medical care for headache. Headache diagnosis in the primary care setting entails differentiating primary from secondary headache. Primary headaches should be assigned a diagnosis of migraine, tension-type, or cluster headache. Secondary headaches are exceedingly rare compared with primary headaches and may require referral to a specialist for additional evaluation or treatment. Although International Headache Society (IHS) criteria can be useful in defining headache types, overly strict application may result in missed diagnoses of patients with disabling primary headaches. Expert opinion and data from clinical studies converge to support the approach of considering a stable pattern of episodic, severe, disabling headache with return to normal function within 24 to 48 hours to be migraine in the absence of contradictory evidence. A brief but complete neurological history should be taken as well as performing physical and neurological examinations. When diagnosing the patient with headache, the clinician should be alert to the possible presence of chronic daily headache arising from medication overuse or uncontrolled migraine. Additionally, patient diaries and disability assessment tools can help identify a pattern of headaches and headache-related disability suggestive of migraine or medication-overuse headache.