Headache is one of the common clinical conditions with a wide variety of types and a particularly complex etiology. Although many headaches originate in or are located in the neck, collar, or occipital region, disorders of the cervical spine or neck are not considered to be the most common cause of headaches. Because cervical degeneration is present in almost all people older than 40 years of age, headache site and radiographic findings of cervical degeneration have been cited as plausible causes of headache, and large controlled pilot studies have shown that such changes are also widely present in people without headaches. As headache continued to be studied, more and more scholars discovered that cervical disorders could also cause headache, and a systematic study of cervicogenic headache was initiated. Definition and Diagnostic Criteria Despite this, the disorders are still very controversial and even the diagnostic term “cervicogenic headache” is not universally accepted. Other terms include cervical headache, cervical migraine, cervicogenic syndrome, occipital neuralgia, occipital headache, third occipital neuralgia, and cremasteric headache. Academic bodies, including the International Headache Society, the International Pain Society, the Cervicogenic Headache International Study Group, and the World Cervicogenic Headache Society, have not reached consensus on the definition of cervicogenic headache. These groups disagree on whether the headache is unilateral or bilateral, the importance of imaging studies, and the relevance of associated factors. Cervicogenic headache seems to be literally easier to understand and accept anatomically and physiologically than migraine and tension-type headache, but as can be seen from the brief historical review above, this concept is not widely accepted due to the lack of consensus.The Cervicogenic Headache International Study Group led by Sjaastad defines cervicogenic headache as a chronic, unilateral headache caused by organic or functional lesions of the cervical spine and/or soft tissues of the neck that is characterized by The International Study Group on Cervicogenic Headache, led by Sjaastad, defines cervicogenic headache as a group of syndromes in which chronic, unilateral head pain is the main clinical manifestation and the nature of the pain is a form of referred pain, with special emphasis on diagnostic anesthetic block as one of the diagnostic criteria for cervicogenic headache. In the second edition of the International Headache Society’s 2004 classification criteria for headache disorders, cervicogenic headache was classified as a subtype of headache attributable to cervical disorders, while retropharyngeal tendonitis, which was one of the diagnostic criteria for cervicogenic headache in the first edition, was classified as a subtype alongside cervicogenic headache, and headache attributable to abnormal craniocervical muscle tension was classified as a subtype alongside it, while headache with pericranial pressure pain or Headache with pericranial pressure or cervical fascial pressure points is classified as a subtype of tension-type headache, and headache due to whiplash is classified separately. The new classification of the International Headache Society narrowed the meaning of “cervicogenic headache” in a literal sense, but I believe that this is only the result of a more detailed classification, as the new classification states that the purpose of the criteria is not to describe individual subtypes, but to establish a specific causal relationship between headache and neck disorders. These two academic groups are very influential internationally, thus resulting in different and confusing definitions of cervicogenic headache in the domestic and international literature, but after all, it is only a matter of conceptual connotation and extension, without much difference in essence. In view of the confusion of the current definition and diagnostic criteria, the author recommends the adoption of the International Study Group of Cervicogenic Headache diagnostic criteria in clinical work. The content is as follows: 1. Neck symptoms and signs. (1) Headache symptoms are aggravated by the following conditions. (1) When the neck is moved and/or the head is maintained in an abnormal position; (2) When pressure is applied to the upper neck or occipital area on the side of the headache. (2) Restricted range of motion of the neck. (3) Ipsilateral non-root pain in the neck, shoulder or upper extremity (localization is unclear), or occasional root pain in the upper extremity. 2.Diagnostic anesthetic block may clarify the diagnosis. 3.Unilateral headache without transfer to the contralateral side. Clinical manifestations Cervicogenic headache is mostly on one side, or unilateral headache with alternating bilateral attacks (if both sides of the neck are involved at the same time, the headache may occasionally be bilateral), and rarely is it a full headache; the headache starts in the cervical-occipital region, and may spread along the cervical-occipital region to the parieto-temporal region, and rarely occurs in the forehead or supraorbital region, with the most severe pain in the cervical-occipital region. The headache is often accompanied by tinnitus, vertigo, hearing impairment, nausea, vomiting, photophobia, fear of sound, and in a few cases, eye swelling or sunken eyes, unequal pupils, tearing, and conjunctival congestion. Thus, it is not easy to distinguish from primary headache such as migraine, cluster headache and tension-type headache; the headache has many excitation points, which are located in the cephalicus, trapezius, sternocleidomastoid muscles and suboccipital muscles (C1-3 innervation). In conclusion, cervicogenic headache has a significant proportion of the population and is a common secondary headache. In the future, there is a need to further strengthen the understanding of it, conduct more in-depth research on the pathogenesis, improve and unify the diagnostic criteria, and explore more effective treatment methods.