What kind of diseases can be treated by the herbs that clear Heat? How should one choose the herbs in clinical practice?
Heat in the Lung and Large Intestine
The Lung is, in TCM, considered a delicate organ. Heat or Cold easily injures it. If Heat invades the Lung and disturbs its dispersing and descending functions, the patient may have a cough, shortness of breath, wheezing, dryness of the nasal passage and of the lips, and some patients chiefly have skin disease.
To clear Heat and to restore the normal function of the Lung, sweet, pungent, bitter, salty and cold substances are suggested, such as Shi Gao, Zhi Mu, Huang Qin (Scutellariae radix) and Lu Gen (Phragmitis rhizoma).
If Heat disturbs the function of the Large Intestine, the main disorders are abnormal bowel movements and pain in the abdomen. Herbs that regulate bowel movement and clear Heat should be chosen-for instance, Huang Qin, Bai Tou Weng, Qin Pi (Fraxini cortex) and Ma Chi Xian (Portulacae herba).
The throat is the gateway of the Lung and the Heat in the Lung may also influence the throat. In clinical practice, many cases of swollen throat, sensations of obstruction in the throat, hoarseness, and sore throat are caused by Heat in the Lung. Herbs such as Shan Dou Gen (Sophorae tonkinensis radix), She Gan (Belamcandae rhizoma), and Ma Bo (Lasiosphaera) are particularly suitable for this situation. Because they enter the Lung meridian and are pungent, bitter and cold, they are able to clear Heat, relieve Heat-toxin in the throat, and disperse constrained Heat, Phlegm, and Qi in the throat.
Heat in the Kidney and Bladder
The Kidney is an organ that stores the Essence and is believed never to have a real excessive syndrome during pathogenic processes. However, sometimes Empty-Heat in the Kidney can be very strong and may further consume the Essence and the Yin of the Kidney. The symptoms are night sweating, ‘bone steaming’ (a type of fever due to deficiency of Yin, which may not always show when taking temperatures, as though the heat is spreading from the inside of the bone to the outside of the skin), low-grade fever, bleeding gums, spermatorrhea and hypersexuality. Treatment should be given to nourish the Kidney-Yin and at the same time reduce Empty-Fire.
Bitter, salty, sweet, and cold herbs are often used-for instance Zhi Mu, Huang Bai (Phellodendri cortex), Di Gu Pi (Lycii cortex) and Sheng Di Huang. The Bladder stores the urine, but the Kidney controls the opening and closing of the Bladder. If Heat invades the Lower Jiao or the Bladder, then turbid, scanty urine and difficult and painful urination
may appear. Herbs that are bitter and cold and enter the Bladder and Small Intestine meridians should be used to clear the Heat and dry Dampness, or to promote urination, thereby eliminating Damp-Heat; these include Huang Bai, Zhi Mu, Dan Zhu Ye and Long Dan Cao. Apart from treating internal Heat syndromes of the internal organs, herbs that clear Heat can be used for treating acute febrile diseases and pestilence. Acute febrile diseases are caused by pathogenic Heat invasion in different seasons. These pathogenic changes are characterized by a relatively acute onset, predominance of Heat in the initial
stages, and damage of the Body Fluids and Yin. In clinical practice, this is seen in acute infections caused by bacteria, viruses or other pathogenic microorganisms, such as pneumonia, bronchitis, gastroenteritis, and dysentery. Pestilence is a kind of virulent infectious disease caused by Heat-toxin-for instance, epidemic cerebrospinal meningitis, and poliomyelitis. Acute febrile diseases develop in the body following the four levels-that is, Defensive (Wei), Qi, Nutritive (Ying) and Blood (Xue).
Heat in the Defensive level
This is the initial stage of an acute febrile disease. The clinical manifestations are fever, slight aversionto wind and cold, headache, general aching in the body, a slight thirst and sweating, a red tip and border to the tongue, and a superficial and rapid pulse. Treatment must be given to expel Warm pathogenic factor and clear Heat. Herbs that are pungent, cool, or bitter and cold but fragrant and have dispersing properties should be used; these include Chai Hu (Bupleuri radix), Ju Hua (Chrysanthemi flos), Bo He (Menthae herba), Jin Yin Hua and Lian Qiao.
Heat in the Qi level
This is the mid phase of febrile disease. The clinical manifestations are high fever without chills, perspiration, a dry mouth and thirst, red face, shortness of breath, scanty urine, a red tongue body with a yellow coating, and a rapid, forceful pulse. These symptoms indicate that the Heat is increasing inside the body, and it may injure the Body Fluids. Treatment should use sweet, salty, pungent, and cold herbs to clear the Heat, reduce Fire, protect the Body Fluids and vent the Heat to the Defensive level and eliminate it. Herbs such as Shi Gao, Zhi Mu, Jin Yin Hua, Lian Qiao, Zhu Ye and Lu Gen (Phragmitis rhizoma) are often used.
Heat in the Nutritive level
This is the later and critical stage of an acute febrile disease. The clinical manifestations are fever that worsens at night, severe irritability, restlessness, delirium and indistinct erythema and purpura. The tongue body is deep red without a coating; the pulse is thready and rapid. The symptoms indicate that the Heat is very intensive, has disturbed the Mind and Blood circulation, and has injured the Body Fluids and Yin. Herbs that are sweet, salty, bitter and cold are used to reduce the Fire and increase the Body Fluids and Yin, such as Sheng Di Huang, Mai Men Dong (Ophiopogonis radix), Dan Shen (Salviae miltiorrhizae radix) and Xuan Shen (Scrophulariae radix). At the same time, herbs that can bring the Heat to the Qi level should be used. Because the Heat comes from outside, no matter how deep it has invaded the body, it must be eliminated from the inside to the outside. The commonly used herbs are Jin Yin Hua, Lian Qiao and Zhu Ye. Heat in the Blood level This is the most critical stage of an acute febrile disease. The clinical manifestations are fever which is higher during the night, restlessness, obvious purpura, hematemesis, epistaxis, blood in the stools, occasional coma, delirium, convulsions, a deep red or purple tongue without coating and a thready, rapid pulse. The symptoms indicate that Heat-toxin has already entered the Blood, consumed it, disturbed its circulation, and caused bleeding. At this point, treatment should be focused on cooling the Blood and dispersing the congealed Blood in time. Herbs that are cold in nature enter the Blood level and are pungent or with dispersing ability, should be used; these include Mu Dan Pi, Sheng Di Huang, Chi Shao Yao and Dan Shen.
During the recovery stage of a febrile disease, the pathogenic factors are no longer so strong, but the Qi and Yin of the body have also been severely consumed. The main symptoms are fever which starts in the night and disappears in the morning, or a lingering low-grade fever, tiredness, poor appetite, shortness of breath, a red tongue with thin coating or without coating, and a weak, thready, rapid pulse. Herbs that are sweet and cold and enter the Kidney, Stomach or Lung meridians are used to reduce the Deficient-Heat from the Yin level, such as Yin Chai Hu (Stellariae radix), Di Gu Pi and Bai Wei (Cynanchi atrati radix).
