“The Heart Governs Sweat” is one of the 6 stated functions of the Heart in Chinese medicine. Although this may sound surprising to most people who are not familiar with Chinese medicine, even more surprising may be the amount of discussion Chinese medicine has pertaining to sweating.
On a physical level, sweating has to do with the balance between the Wei Qi and the Ying Qi. Wei Qi is coarse defensive Qi that circulates superficially in the muscles and skin. Ying Qi is refined Qi that circulates deeper through the regular meridians. The topic to which these pertain is external pernicious influences, one of the 3 causes of disease in Chinese medicine (the internal causes are the emotions, the external causes are the weather, and the neither internal nor external causes are diet/lifestyle, trauma, and several miscellaneous factors). These pernicious influences are wind, cold, damp, heat, summer heat, and dryness. They enter the surface of the body through the skin and penetrate the acupuncture points, meridians, tissues and organs. The presence or absence of sweating, along with its nature, location, prevalent time of day, and amount, reveal information about both the nature of the pathogen and the defensive Qi of the body. For example, if a person experiences simultaneous chills and fever, along with body aches and an absence of sweating, this indicates a cold invasion (there are many further differentiations of types). If there is sweating, and the sweating does not relieve the illness, this still indicates a cold invasion but with a dysregulation of Wei and Ying Qi. A weakness in the body’s defensive layer permits leakage of sweat from the pores. Herbal formulas for this type of imbalance are centered on Cinnamon Twig Soup.
I mention this formula because it is a good way of leading into a discussion of internally induced sweating disorders. In the context of a Heart imbalance, the same mechanism that causes a person to sweat when they are sick is the same mechanism that causes a person to sweat when they are nervous. That is, dysregulation of the Ying and Wei. In particular, this is a function of the Pericardium and Triple Heater, two of the other fire element organs. These two organs act like gates around the Heart. In health, they are able to spontaneously open and close to regulate the Ying and the Wei – they keep out what needs to be kept out, let in what needs to be let in, keep in what needs to be kept in, and let out what needs to be let out. They form barriers, and regulate the aspect of our fire that encounters the world. Sweating disorders indicate a fire imbalance, a problem with the Heart’s ability to constrain fluids, and possibly an issue related to contact.
Cinnamon twig formulas treat a personality type where excessive or deficient contact is apparent. Thus, the person might be very outgoing, or else shy. A common modification to Cinnamon Twig Soup is to add oyster shell and dragon bone (fossilized wooly mammoth bones), thereby adding an astringing component to the formula. This formula falls under the interesting category of formulas that stabilize and bind. Here, formulas that treat all types of leakage can be found.
Said another way, Qi has five functions in the body. It transforms, transports, warms, protects and holds. Heart Qi holds sweat. Too much sweating is a sign of deficient Heart Qi, and lack of sweating is sign of constrained Heart Qi. Excessive perspiration damages the Qi and wastes the fluids of the body. It is one of the types of leakages of vital fluids that should always be treated quickly. Proper sweating with heat or exercise is considered normal. All of this is why the Chinese say that the Heart governs sweat.