Yuan-source points are the points at which the original qi surfaces and lingers.
On the yin channels, the yuan-source points are the same as the shu-stream points. They are of fundamental importance in tonifying and regulating their respective zang.
“When the five zang are diseased, select the yuan source points.”
On the yang channels, yuan-source points are discrete points lying between the shu-stream and jing-river points. These have a negligible tonifying effect, and little ability to regulate their related fu. Their principal actions are to dispel excess pathogenic factors and treat disorders along their respective pathways.
Palpation of the yuan-source points can indicate the location of disease, as they will often be tender when their respective organ is affected.