In traditional Chinese medicine, there is a saying: "Without proper flow, there will be pain; with proper flow, there will be no pain."  When the meridians in the head are blocked and the flow of qi and blood is impeded, it will cause headaches. Headaches are further divided into "external headaches" and "internal imbalance headaches." External headaches are caused by changes in weather and invasion of wind-cold, leading to colds, fevers and headaches. Such pains come on sudd