Huang Qin – 黃苓 – Radix Scutellariae Baicalensis
Herbs that clear Heat
What are the characteristics of herbs that clear internal Heat? What precautions should be observed when they are used?
According to the characteristics of internal Heat and the principle of treatment that Heat syndrome should be treated by Cold, all the herbs that clear Heat are cold in temperature. Because of their other properties, the individual herbs also have specific functions. The characteristics are as follows.
Pungent and cold
Pungency has a dispersing action; Cold may clear Heat. The former moves upwards and outwards, the latter moves inwards and downwards. In herbs that clear Heat, their cold property is stronger than their pungent property, therefore the main direction of the herb is downward. Herbs with both pungent and cold properties can more easily clear Heat than herbs with only a cold property. Because pathogenic Heat has a tendency to ascend and the cold herb has a tendency to descend, there is a severe conflict between the Cold and Heat.
Cold herbs are able to suppress pathogenic Heat in very high dosage, so the Heat has to move downwards. But constrained Heat does not agree with Cold herbs and it hides itself in the body. As soon as the patient stops taking the cold herbs, the Heat spreads again. In clinical practice, some chronic infections, such as persistent sinusitis, bronchitis, gastroenteritis, dysentery, hepatitis, and urinary tract infection, are the result of using high dosages of cold herbs or antibiotics.
Pungent-cold herbs are able to clear Heat completely without the possibility of producing constrained Heat or hidden Fire and are more suitable for this pathological situation. As pungency can disperse and lift Fire, it can divide the strength of Heat and reduce the conflict between the cold herbs and the Heat pathogenic factor. Thus pungency can assist the cold property of herbs to reduce Fire when the Fire shows itself clearly. These are especially effective for treating intensive Heat, constrained Heat, and Fire blazing upwards. They are also used when there is Blood stagnation caused by Heat. Examples include Shi Gao (Gypsum), Xia Ku Cao (Prunellae spica) and Mu Dan Pi (Moutan cortex).
Sweet and cold
Sweetness possesses tonifying and harmonizing abilities. Cold can clear Heat so that it may protect the Body Fluids and Yin. Sweet and cold herbs are effective for reducing Heat and protecting the Body Fluids as well as increasing them when they have been injured by Heat, and for relieving thirst. They are used when Heat is in the Qi and Nutritive levels in acute febrile diseases. The herbs Shi Gao (Gypsum), Lu Gen (Phragmitis rhizoma), Sheng Di Huang (Rehmanniae radix) and Tian Hua Fen (Trichosanthis radix) possess these properties.
Salty and cold
Saltiness possesses purging and softening actions. It enters the Kidney and the Blood. The salty-cold herbs may reduce Heat and descend Fire, protect the Blood and Yin, and increase the Body Fluids and Yin which have been consumed by Heat. Their effect of directing Heat downwards is stronger than that of pungent-cold herbs or sweet-cold herbs.
They mainly treat the syndrome of Heat in the Nutritive and Blood levels in acute febrile diseases. Herbs such as Qing Dai (Indigo naturalis) and Xuan Shen (Scrophulariae radix) are the commonly used ones.
Bitter and cold
Bitter substances have a draining ability and a dry nature. Bitter-cold herbs are able to direct Heat or Damp-Heat downwards, reduce Fire, and relieve Fire-toxin. Bitter-cold substances treat syndromes of Excess-Heat in the internal organs and in the Qi level, and are used for acute infectious diseases, sores, boils, carbuncles and skin disorders. Examples include Huang Lian (Coptidis rhizoma), Huang Qin (Scutellariae radix), Huang Bai (Phellodendri cortex), Zhi Zi (Gardeniae fructus), and Long Dan Cao (Gentianae radix).
Generally speaking, to treat Excessive-Heat, herbs with pungent-cold, bitter-cold and sweet-cold properties should be used, and especially those herbs that enter the Lung and Stomach, Liver and Heart meridians. If the pathogenic Heat is not very strong but the Body Fluids have been injured, then sweet-cold and salty-cold herbs that enter the Liver and Kidney meridians are often chosen.
What precautions should be observed in the use of these herbs?
Most of the herbs that clear Heat are bitter and cold. They can quickly and strongly clear Heat and reduce Fire in the related organs and places. However, these herbs cannot be used for a long period of time with high dosage; otherwise they may cause a hidden Heat syndrome, the common side effect of bitter-cold herbs. Because pathogenic Heathas a tendency of ascending and the cold herb has a tendency of descending, a severe conflict between the nature of Cold and Heat develops. Cold herbs are able to suppress pathogenic Heat when their dosages are very high, and the Heat thus has to move downwards; however, as Heat does not agree with the cold nature of the herbs, it withdraws and becomes constrained and hides itself in the body. As soon as the patient stops using the cold herbs, the constrained Heat is free from suppression and it spreads again. In clinical practice, some chronic infections, such as sinusitis, bronchitis, gastroenteritis, and urinary tract infection, are the result of using high dosage of cold herbs or antibiotics. Therefore, a small amount of aromatic or pungent herbs that follow the nature of Fire and disperse constrained Fire should be used with the bitter and cold herbs in order to clear the Heat completely. Generally speaking, cold herbs, and especially bitter-cold herbs, can easily injure the Yang and produce Dampness, so they should not be used for too long and at a large dosage. Bitter-cold herbs may also easily injure the Stomach and may cause stomach cramps and pain, so a proper dosage and a proper course should be arranged carefully. Also, patients with a weak constitution, or suffering from Cold in the Middle Jiao, or weakness of the stomach and intestines, should not use cold herbs in too great a quantity or for too long.
