When I first learned about Chai Hu, I learned that, among other functions, it serves to “raise the Yang Qi.”  In combination with Huang Qi, it is used for this purpose in Li Dong-Yuan’s Bu Zhong Yi Qi Tang.  Because this function has been attributed to Chai Hu, I learned that I must be very cautious using it.  I could over raise the Qi.  My guess is that other practitioners are familiar with this caution as well.  I was under the impression that I could, in using Chai Hu, raise the pressure in a person’s upper body by sending the Yang up.  Indeed, the Formulas and Strategies cautions us to avoid using Chai Hu in cases in which the liver Yang is rising pathologically.  Many practitioners take this to the extreme of avoiding Chai Hu for any case of headache or hypertension.  Zhang Xi-Chun cautions us in this respect as follows:

“For raising the liver, Chai Hu is the most effective.  However when there is a pattern of liver not rising and stomach not descending, Ma Ya should be used instead of Chai Hu.  This is because, Chai Hu not only raises the liver, it also can excessively raise the stomach Qi. On the other hand, Mai Ya can not only raise the liver, it also does not hamper the descending of stomach Qi.  The nature of this sprouting new growth has an affinity for wood.  It can open-through and spread constraint and knotting of liver wood.  This opening and resolving naturally leads to ascending”

I would like to challenge this concept.  I see it as an unfortunate misunderstanding.  I have my own thoughts about it but first, I will quote Li Ke.  He writes:

Five phase theory tells us that wood can insult the earth.  Because of this we can also know that wood can disperse the earth.  While excessively strong constraint of wood Qi can insult earth, weakness of liver Qi can also fail to disperse earth.  In terms of the treatment of liver and spleen constraint patterns, Master Zhang opened up his own pathways in order to resolve and reveal clinical conundrums.  However, I do not accept the theory that “Chai Hu can excessively raise the stomach Qi.”  Contemplate the fact that the Da and Xiao Chai Hu Tang patterns include the principle symptoms of stomach Qi rebelling upward, desire to retch and ceaseless vomiting along with the fact that Chai Hu is the principle herb in these formulas.  In fact, half a Jin of Chai Hu is used.  This is 125 grams according to ancient and modern equivalencies.  This is a very large dose, and is about 1/3 of the whole formula.  This can stop extreme vomiting.  I have used these formulas thousands and thousands of times.  We can say beyond a doubt that Chai Hu does not excessively raise the stomach Qi.

According to the principles of the ascending and descending of the Qi mechanism, the spleen and stomach are the central axis.  This is like the axis of a wheel and is the central Qi.  The spleen rises and the stomach descends.  This is what allows for the rotational movement of the central Qi.  The liver rises from the left and the lung descends from the right.  When rising and falling happen as they should, there is no disease.  There is also the subtle effect of the channels that herbs home to.  Herbal functions are not limited to one factor.  The application of the herbs in the Shang Han Lun is miraculously subtle and is not limited to one method.  While raising the liver, it also can descend the stomach. The implication of wood overcoming earth is that the raising and expanding of wood courses and discharges and the benefits the spleen and stomach of the damp earth.  It does not congest it.  When Chai Hu raises the liver, it does not hinder the stomach.  This is the normal transformations of the five phase generation and restraining functions.

I see that his arguments are strong indeed!  He aptly brings Zhang Zhong-Jing himself into the debate.  When he writes about how wood can either act against or benefit earth, I think of how roots of plants and either choke soil or aerate and support soil.  Wood, in relation to earth, is not bad or good.  It just depends on whether it is too strong, not strong enough or just right.   I couldn’t agree more and yet, I’d like to go a step further.

《Su Wen 天元紀大論 Tian Yuan Ji Da Lun》
Emperor fire uses clear light, minister fire uses position.

I’d like to now add my own two-cents to the discussion.  If we contemplate the relationship between the Shao Yang pivot and the ministerial fire, we can start to see that the function of Shao Yang is to take the fire that is coming down from the heart to the kidney and pivot it into its proper position.  Ministerial fire, placed as it is in the lower Jiao, functions by going upward.  It is the proverbial fire under the cooking pot in our bodies.  The source of this fire is the imperial fire that comes from above, but to be functional for our bodies, this fire must change direction from downward to upward.  This requires a pivoting action.  Enter Shao Yang!  If we see the function of Shao Yang as helping turn this pivot so that ministerial fire can be in position, then the primary action of Chai Hu is to turn the Shao Yang pivot.

Shao Yang pathology then is what happens when this pivot does not turn as it should.  Here’s what happens, the heat that is meant to turn into position in the Dan Tian internal region, gets stuck outside of this region.  This is why heat is often a factor in Shao Yang pathology.  It is actually heat that is meant to be physiological, building up to be pathological.  This heat, being out of right relationship with the body, will have a tendency to flare upward.  In addition, the lack of proper ministerial fire working in the Dan Tian, will create a cold, stagnant situation in the next conformation, Tai Yin.  This can lead to all manner of digestive upset and a general malfunction of the ascending and descending of the spleen/stomach axis.

Chai Hu then is like oil on a hinge.  It helps the pivot turn as it should.  Then what happens?  Flaring fire is now put in its place under the cooking pot of the body!  Chai Hu is acting to descend in this way.  Ministerial fire, now being in its correct position, can do its work of transforming and rising, but this time, physiologically.  Not pathologically.  By warming and activating Tai Yin, the ascending and descending of the spleen/stomach axis now functions.

In this way, Chai Hu neither ascends, nor descends.  It simply, with the help of Huang Qin, facilitates the proper turning of the pivot.  Thereby, ascending and descending naturally occur as they are meant.

Hence, the symptoms that Zhang Zhong-Jing mentions for formulas such as Xiao and Da Chai Hu Tang, are not symptoms of a pathogen IN Shao Yang.  They are symptoms of the pivot not functioning well. Our diagnosis is focused on being able to ascertain the functioning of the pivot.  Our treatment does not go in and try to lift what is fallen or descend that which is going up.  It is the bodies job to ascend and descend.  We fix the body so it can do this itself.