Objective. -To examine the associations between severe headaches (SH), psychological distress, and comorbid conditions among U.S. adults. Background. -The lifetime prevalence of headaches is over 90%and headaches, particularly migraines, have been associated with disability, increased healthcare costs, and mood disorders. Methods. -We analyzed data obtained from adults aged 18 years or older (n = 29,828) who participated in the 2002 National Health Interview Survey, an ongoing, computer-assisted personal interview of a representative sample of the U.S. population. Results. -Approximately 15.1%of adults aged 18 years or older reported SH in the previous 3 months. Those reporting such headaches were significantly more likely, than those who did not, to report insomnia, excessive sleepiness, recurrent pain, and depressive or anxiety symptoms during the preceding 12 months. Approximately 88%of those who reported having had SH within the previous 3 months also indicated that they had at least one comorbid medical condition, relative to 67%of those without SH. Conclusion. -Despite their episodic nature, our results suggest that SH are associated with impairments in both physical and mental health. As the presence of SH may serve as an indicator of significant psychological distress and medical comorbidities, eliciting information about their occurrence during a standard medical examination appears to be warranted. Objective -To examine the associations between severe headaches (SH), psychological distress, and comorbid conditions among US adults. Background. -The lifetime prevalence of headaches is over 90% and headaches, particularly migraines, have been associated with disability, increased healthcare costs, and mood disorders. Methods. -We analyzed data obtained from adults aged 18 years or older (n = 29,828) who participated in the 2002 National Health Interview Survey, an ongoing, computer-assisted personal interview of a representative sample of the US population. Results. -Approximately 15.1% of adults aged 18 years or older reported SH in the previous 3 months. Those reporting such headaches were significantly more likely, than those who did not, to report insomnia, excessive sleepiness, recurrent pain, and depressive or anxiety symptoms during the preceding 12 months. Approximately 88% of those who reported had had within 3 months also indicated that they had at lea Conclusion one of them without SH. Conclusion. -Despite their episodic nature, our results suggest that SH are associated with impairments in both physical and mental health. As the presence of SH may serve as an indicator of significant psychological distress and medical comorbidities, eliciting information about their occurrence during a standard Medical examination appears to be warranted.