Clearly the patient's history is paramount in determining whether a headache belongs in the migraine, chronic tension-type or other category. The multiple conditions in the other category can sometimes make definitive diagnosis a daunting challenge. Laboratory testing looking for hematologic or metabolic abnormalities may be advised, and brain imaging may be required. If an acute hemorrhage is anticipated, an unenhanced CAT scan may be sufficient. Relative to other pathologic possibilities, a MRI generally provides more specific and useful information. This is especially true when seeking to rule out a tumor or vascular abnormality (in which case a MRA, as well as a MRI, may be helpful). Most lay people recognize that headaches may, at least potentially, have a serious cause. Indeed, many patients with severe migraine and chronic tension-type headaches are greatly relieved to learn that some ominous pathology is not present. Of course, clinicians also worry about the causes of headache and are fearful of missing some potentially serious underlying pathology. Utilization of the conceptual framework of migraine, chronic tension-type or other headache does not guarantee an accurate diagnosis. But this approach can help, especially when the clinician appreciates the importance of an accurate patient history. Such focus can guide the determination of whether to initiate empiric treatment or to embark on a definitive diagnostic evaluation. Headaches are common, sometimes disabling and potential harbingers of dreaded pathology. Thoughtful assessment of every patient with headache is warranted.