Comorbidity refers to the presence of an additional co-existing ailment in a patient with a particular index disease. Migraine co-morbidities have been reported in various clinical and case control studies. Comorbidities impose a high socio-economic burden on society and compromise the quality of life in migraineurs. There are several factors which can complicate the investigation of co-morbidity. They have to be differentiated from migraine equivalents. Abdominal pain, vertigo or visual hallucinations in migraineurs may suggest an alternative diagnosis or may be confused with comorbidities. The goal of this review is to help identify comorbidities in diagnosed cases of migraine and to understand their overall impact on this complex headache disorder.