Headache is a common source of morbidity in the US population, and its burden is substantial. The prevalence of various types of headaches such as migraine ranges from 7 to 16% across countries. In the US, its prevalence ranges from 6% in men to 18.2% in women. In 1998, the direct costs of migraine were estimated to be about $1 billion, and the indirect economic costs for people aged 20-64 years were estimated to be about $12 billion. In 2002, the cost of lost productive time due to headaches was estimated at almost $20 billion. In addition, headaches are a major determinant of impaired quality of life.

Because of the considerable burden imposed by headaches on populations in the US and elsewhere, an understanding of potentially modifiable risk factors for this condition is key to helping to reduce the morbidity associated with it. In recent years, researchers have examined possible associations between obesity and headaches. Given the rapid increase in obesity in the US, a possible link between obesity and headaches is of considerable interest and would suggest new avenues for reducing the public health burden of headaches. Therefore, the objective of this study was to examine the association between body mass index and headaches in a national sample of US adults.