Sixth difficulty of Nanjing, classic of difficult issues

陰 陽 虛 實 false and true yin and yang

六 難 sixth difficulty
論 脈 之 陰 陽 虛 實 explains false and true yin and yang of pulse
六 難 曰 ：sixth difficulty explains
脈 有 pulse has
陰 盛 yin abundant
陽 虛 ，yang deficient
陽 盛  yang abundant
陰 虛 ，yin deficient
何 謂 也 ？what does it mean?
然 ： explanation
浮 之損 小 ，decreasing in surface
沉 之 實 大 ，increasing in depth
故 曰 they say
陰 盛 yin abundant and
陽 虛 。yang empty
沉 之 損 小 ，decreasing in depth
浮 之 實 大，increasing in surface
故 曰 they say
陽 盛 yang abundant
陰 虛 。yin deficient
是 陰 陽 虛 實 之 意 也 。it is a meaning of false and true yin and yang

Sixth difficulty of Nanjing explains movement of Rong and Wei Qi towards the surface or towards the depth. It indicates if Qi moves from Zhong into Fu meridian, from meridian into Wei area or backwards during yin or yang period. This natural Qi flow may be controlled through acupuncture pulse diagnosis and used for successful needling. This difficulty helps to treat a real disease instead of false. This difficulty differentiates increasing force as true yin or yang and decreasing force as false yin or yang, which also stated in forth difficult issue. 
Direction of Qi flow is not used lately in acupuncture as modern TCM uses herbal pulse diagnosis where this direction is not important for a treatment. Ancient acupuncture pulse diagnosis can show where to start the treatment, what to treat, what is true condition and what is result of that. 
Finding direction of Qi flow will give light on activity of meridians which depends on astronomical solar noon and may be find through the pulse and not by clock. This activity obviously isn't a two hours, but one hour and fifty two minutes each as pulse shows.
You may be interested to take hands-on practical online seminar to find out how to do this or any other acupuncture pulse diagnosis ancient methods based on Nanjing to improve your practice.

Pulse Diagnosis For Practitioners from easy to difficult