There is increasing evidence that migraine and muscle contraction headaches are similar; rather than being different entities, they may vary in symptom quantities instead of having qualitative differences. Analysis of elements of the headache history in 50 consecutive idiopathic headache patients failed to show evidence for distinct headache types. Quantitation of symptoms and characteristics showed a unipolar distribution; reported pain severity was directly related to the symptom quantitation score. These two statements were true for three different history scoring systems, from the simplest (quantitation of nausea, unilaterality and aura) to the most detailed (quantitation of nausea, unilaterality, aura, photophobia, throbbing pain, headache location, family history and clustering). Headache scores were lower for patients previously diagnosed as “tension” headache patients compared to those diagnosed previously as having “migraine”. Joint occurrence of the major migraine symptoms of nausea, aura and unilaterality was by chance. These data support the headache severity model described by others, and do not support the existence of separate, distinct idiopathic headache entities.