Etiology and Pathogenesis Wind cold Invasion of wind on the External Wind heat vertex and external evils factors causing obstruction of the Wind meridians and collaterals Obstruction dampness Flaring-up to the orifices Headache resulting in stagnation of qi leading Liver Yang and blood Obstruction of the clear orifice Turbid phlegm unsmooth flow of qi and blood in Internal vessels and collaterals headache factors Blood stasisObstruction of the meridians Failure to Kidney Failure of the sea of一 nourishing the deficiency marrow to be nourished head Etiology and Pathogenesis External factors Internal factors Wind cold Wind heat Wind dampness LiverYang Turbid phlegm Blood stasis Kidney deficiency Invasion of wind on the vertex and external evils causing obstruction of the meridians and collaterals Flaring-up to the orifices resulting in stagnation of qi and blood Obstruction of the clear orifice unsmooth flow of qi and blood in vessels and collaterals Obstruction of the meridians Failure of the sea of marrow to be nourished Failure to nourishing the head Obstruction leading to headache Headache