Headache is the most common of the many symptoms seen after concussion or even seemingly trivial head injury, and, as such, is an important component of the controversial and often difficult-to-treat postconcussion syndrome (PCS). Because PCS, or its equivalent is seen in occasional patients with whiplash, it has also been referred to as posttraumatic syndrome. Unfortunately, this terminology is too easily confused with posttraumatic stress disorder. PCS has therefore remained the prevalent terminology in describing the bulk of posttraumatic symptoms. An extensive literature is available regarding posttraumatic headache (PTH). Among the resources is the International Headache Society (IHS) Classification System. The IHS criteria, which were developed in 1988, have never taken hold in primary care as a practical clinical classification system. This is largely due to their unwieldy length and thoroughness and partly due to a tendency for physicians to utilize preceding classifications already well understood.