Headache

Headache is one of the most common but poorly understood pain conditions. Surprisingly, little is known about putative mechanisms of headache, though research is advancing and creating new therapeutic targets. The taxonomy of headache is complex, and this chapter will describe how various headache types are diagnosed, assessed, and treated. Most of the chapter will focus on primary headaches (which affect up to 80% of the global population). Some secondary headaches will receive additional attention. Controversies related to headache classification and treatment are also discussed.