1	G44.0	Cluster headache syndrome	0
2	G44.1	Vascular headache, not elsewhere classified	1
3	G44.2	Tension-type headache	1
4	G44.3	Chronic post-traumatic headache	1
5	G44.4	Drug-induced headache, not elsewhere classified	1
6	G44.8	Other specified headache syndromes	1
7	G44	Other headache syndromes	1