RT Book, Section A1 Hamelsky, Sandra W. A1 Stewart, Walter F. A1 Lipton, Richard B. A2 Warfield, Carol A. A2 Bajwa, Zahid H. SR Print(0) ID 3410980 T1 Chapter 17. Epidemiology of Headaches T2 Principles & Practice of Pain Medicine, 2e YR 2004 FD 2004 PB The McGraw-Hill Companies PP New York, NY SN 9780071443494 LK accessanesthesiology.mhmedical.com/content.aspx?aid=3410980 RD 2024/03/28 AB Headache is a common pain symptom that inflicts a substantial burden on individual sufferers and on society. Headache has many causes; a range of headache diagnoses was defined by the International Headache Society (IHS) in 1988.1 The IHS distinguishes two broad groups of headache disorders: primary headache disorders and secondary headache disorders. Secondary headache disorders result from an underlying condition, such as a sinus infection or brain tumor. In primary headache disorders, the headache disorder is the fundamental problem. The two most common types of primary headache disorders are episodic tension-type headache (ETTH) and migraine.