The Lung is an important organ in Exterior syndrome because it governs the Exterior by dispersing the Defensive Qi to the superficial layer of the body. Moreover, Wind-Heat and Dryness can directly disturb the function of the Lung because they can invade the body through the nose, and not the superficial level.

The main symptoms can be divided into two groups. On the one hand, chills, fever and aversion to cold or wind are present. These are the manifestations in the superficial layer of the body caused by the conflict between pathogenic factors and the Defensive Qi. On the other hand, headache, general pain, thirst, blocked nose, cough and sore throat may be present; these are manifestations caused by disharmony of the circulation of the Qi and Blood in the Bladder meridian and dysfunction of the Lung-Qi.

The purpose of treatment is to expel the exogenous pathogenic factors, and to restore the normal functioning and harmony of all the organs, meridians, Qi and Blood. Methods that can stimulate or strengthen the function of the Defensive Qi or disperse the Lung-Qi and therefore eliminate the pathogenic factors are often used. Other methods, such as promoting Qi and Blood circulation, or regulating the Large Intestine in order to regulate the Lung-Qi, can also be used as assistant procedures in the whole treatment strategy.

Herbs that release the Exterior have the functions of expelling Wind-Cold or Wind-Heat. They are used in conditions where the pathogenic Wind-Cold or Wind-Heat invades the superficial layer of the body. They have the following properties.

First of all, since herbs that release the Exterior are pungent and their tendencies of action are ascending and dispersing, especially with the herbs that can cause sweating, overdose may disperse the Qi too much, consume the Yin of the body and cause other complications. In patients who are deficient in Yin or Qi owing to their constitution, chronic disease, stress or dietary habit, these herbs should be used with caution. Furthermore, as pungency also has the property of movement, these herbs should also be used with caution in bleeding conditions or in pregnancy.

Secondly, the dosage of herbs should be adjusted to suit the condition of the individual, the syndrome and the season. For elderly people, children, people with a weak constitution and for mild syndromes, in a gentle climate and in the summer, the dosage should be reduced. For adults with a strong constitution and for severe syndromes, in a cold winter or a cold place, the dosage should be increased. If sweating must be induced, the dosage is adjusted according to the syndrome. A mild sweat over the whole body is required. Heavy sweating must be avoided because it can only weaken the Qi and Yin.

In the third place, as eliminating Wind-Cold or Wind-Heat is not generally difficult, these herbs should not be used for a long period of time. A dosage of 3 days is recommended to treat Exterior syndrome. If the exogenous pathogenic factors have not been removed completely, then another 3-day dosage can be prescribed. With regard to herbs that may cause heavy sweating, the dosage and treatment course should be adjusted according to the reaction of the patient after each use.

Ma Huang and Gui Zhi can expel Wind-Cold and treat Exterior Wind-Cold syndrome. Compared with Gui Zhi, Ma Huang is stronger in inducing sweating and expelling Wind-Cold from the surface of the body. This is because Ma Huang is very pungent and warm, and its speed of movement and strength are stronger than Gui Zhi. When Wind-Cold attacks the body surface, the pores are closed by Cold, which is characteristically contracting, so the Defensive Qi is not able to spread over the surface of the body. In consequence, the patient feels chilly because the surface of the body is not warmed up by the Yang and Qi. The blockage of Defensive Qi inside may then produce Heat and the patient may have a fever. Because Cold initially injures the Yang-Qi in the Greater Yang ( Tai Yang) meridian, this stops the Qi circulating freely, and the patient feels pain and stiffness in the back of the body. Due to dysfunction of the dispersion of Lung-Qi, there are also cough and shortness of breath. Ma Huang enters the Lung meridian, disperses the Lung-Qi, enters the Bladder meridian, activates the Defensive Qi, opens the pores, causes sweating and expels Wind and Cold so that the Exterior can be released. This herb is considered as the strongest one for causing sweating. It is the first-line choice where Wind-Cold is severe and the patient has severe chills and fever without sweating, such as in upper respiratory tract infection, cold infections, influenza, acute bronchitis, pneumonia and asthma.

Gui Zhi can also treat Wind-Cold syndrome. Here the therapeutic result is achieved by warming the Blood, promoting Blood circulation, opening up the meridians and activating the Yang-Qi to expel Wind and Cold. Compared with Ma Huang, Gui Zhi is not so warm and pungent, but sweet. It enters the Heart meridian primarily, and the Lung and Bladder meridians secondarily. The warm nature of this herb can reduce Cold in the Blood. Pungency and warmth may also activate the Blood circulation and open up the meridians. The sweetness moderates the warmth and pungency so that the medicinal action may be balanced. As it enters the Lung and Bladder meridians, it can activate the Yang-Qi to eliminate Wind and Cold in the Exterior layer. When the pathogenic Cold is not so severe, the pores are not closed so tightly, which manifests as slight sweating or a milder cold sensation and less pain in the back of the body, Gui Zhi can be used alone. It is especially useful for patients with Exterior syndromes against the background of a Yang-deficient constitution, Bi syndrome or Cold in the Blood, such as in elderly people, patients with chronic bronchitis, pulmonary emphysema, rheumatism or Raynaud’s disease.

In clinical practice, Ma Huang and Gui Zhi are often used together to treat severe Wind-Cold syndrome, as they work on different aspects—for instance, the former enters the Qi level, the latter enters the Blood level; the former induces sweating and eliminates Wind-Cold by a short, quick and strong action, the latter promotes the Blood circulation, warms it, stops pain and activates the Yang-Qi in the Blood, thereby expelling Wind-Cold. When they are used together, the therapeutic effects are enhanced.

Although there are differences between Ma Huang and Gui Zhi, they both belong to quite warm and pungent herbs in the herbal group of expelling Wind-Cold. The dosage should be carefully managed. Age, constitution and the present state of health should also be considered. Generally speaking, after taking these herbs, if the patient does not sweat, the dose should be increased within the normal dosage range. If the patient becomes sweaty and the chills and fever are less severe, Ma Huang and Gui Zhi should not be used again. Some herbs with a gentler action can be substituted, such as Jing Jie ( Schizonepetae herba) and Fang Feng ( Saposhnikoviae radix). If, after a while, the chills and fever return, Ma Huang and Gui Zhi should be used again but in a smaller dosage as the Wind and Cold have already been partially expelled.

Moreover, as the tendency of action of these two herbs is upward and outward, in the following conditions they should not be used or used with caution: patients suffering from acute infection of the nose and throat where there is internal Heat or Heat due to Deficiency in the body, patients suffering from hypertension which indicates a tendency to Liver-Yang rising, or women suffering from menopausal syndrome with hot flushes and night sweats, and people with a Yang constitution or with heart disease, because these herbs can increase the contraction of the cardiac muscle and increase oxygen consumption, which makes the heart overwork.

Ma Huang is also called Sheng Ma Huang. ‘S heng’ means ‘raw’. Sheng Ma Huang is very pungent and warm. It is a very strong herb used to expel Wind and Cold to release Exterior Wind-Cold syndrome. As Sheng Ma Huang is pungent and hot, the dosage should be controlled and it should not be used over a long period of time. Overdose may cause heavy sweating, which injures the Yin, Body Fluids and Qi. It should be used with caution, especially in patients with a weak constitution and Deficiency syndrome. As its actions have an upward and outward tendency, Ma Huang should not be used or used with caution in cases of hypertension and heart disease.

Zhi Ma Huang is gentler in action compared with Sheng Ma Huang, because roasting with honey moderates the pungent taste. Zhi Ma Huang acquires the nature of honey, which is sweet and moistening, so its dispersing action is not as strong and quick as that of Sheng Ma Huang. It is often used to disperse the Lung-Qi and cause it to descend, to moisten the Lung and stop wheezing. In clinical practice, it is often used for treating asthma, bronchitis, pneumonia and acute nephritis.

Ma Huang Gen has completely different characteristics from both Sheng Ma Huang and Zhi Ma Huang. It is neutral, sweet and astringent, and enters the Lung meridian. It is excellent for stopping sweating. It can be used for treating spontaneous sweating and night sweating. It treats only the symptoms however, so it is often combined with other herbs that treat the cause of sweating. In addition, it should not be used in the syndrome of Phlegm accumulation or Exterior syndrome because it has an astringent property, which can retain Phlegm, close the pores and retain the pathogenic factors within the body.

‘Twig of plants enters the limbs of human body’: such similes and allegories were often used in ancient times in Chinese medicine to explain the complicated links between the human and the natural environment. Gui Zhi is an example of this. This herb is the twig of the plant and has a warm, pungent and sweet nature. Besides expelling Wind and Cold to treat Exterior syndrome, Gui Zhi is often used to treat Bi syndrome. In this case, it can relieve pain and cold sensations in the affected limbs or joints. The therapeutic effects are achieved by warming and strengthening the Heart-Yang, promoting the Blood circulation, spreading the Yang-Qi and unblocking the meridians, especially in the limbs. This is why it is often used in Bi syndrome caused by blockage of the circulation of Qi and Blood by Wind, Dampness or Cold; examples are rheumatic fever, rheumatoid arthritis, rheumatic heart disease, Raynaud’s disease and the early and mid phases of vasculitis.

In chronic diseases, when internal Cold blocks the meridians, a small amount (about 10 m) of Gui Zhi alcohol drink is also a preferred formulation for daily use in the diet. Soaking 15 grams of Gui Zhi in a liter of alcohol (about 40% alcohol) made from cereals for 6 weeks yields Gui Zhi alcohol drink. Alcohol is pungent and warm, so is considered to have the functions of invigorating the Blood and unblocking the meridians. The functions of Gui Zhi and alcohol therefore enhance each other. It is commonly used for chronic Bi syndrome.

As Gui Zhi is pungent and warm, it should be used with caution if there is any deficiency of Yin with Empty-Fire or Liver-Yang rising in the syndrome or in the treatment of Heat-type Bi syndrome.

Jing Jie and Fang Feng are both pungent and warm. However, they are far gentler than Ma Huang and Gui Zhi. They can expel Wind and Cold and are commonly used for mild Exterior Wind-Cold syndrome. In regions with temperate climates, where Wind and Cold do not close the pores tightly, they are more often applied than Ma Huang and Gui Zhi for cold infections, influenza, certain stages of infectious childhood diseases and some skin diseases in which Exterior syndromes are involved. Meanwhile, they are also often used with pungent-cold herbs in syndromes where Wind-Heat is mixed with Wind-Cold. The patient may have symptoms such as chills, fever, thirst, sore throat and general pain. These two herbs are more often used in combination with cold herbs than Ma Huang and Gui Zhi.

Comparing Jing Jie with Fang Feng, Jing Jie is lighter and more dispersing. It is pungent but not strong, slightly warm but not dry. It is especially good at expelling Wind, no matter whether it is Wind-Cold or Wind-Heat. Moreover, it can expel Wind from the Blood so is often used in skin disorders when there is itching caused by Wind invasion, for instance in eczema, urticaria and food allergy. It is also used for infectious childhood diseases with Exterior syndrome and skin eruptions, such as measles, rubella, scarlet fever, chickenpox and so on.

Although both herbs are gentle, they do have a pungent and warm nature, so both should be used with caution in patients without Wind invasion or in Yin deficiency with Empty-Heat.

Generally speaking, Jing Jie Sui is more thin-pungent than Jing Jie as it is the bud, which is believed to be lighter in nature. It has a quicker and lighter action in expelling Wind. It is used at the very beginning of Wind-Cold syndrome or Wind-Heat syndrome.

Comparing raw with roasted Jing Jie, raw Jing Jie is more pungent. It is used for Exterior Wind-Cold syndrome when sweating is not present, which means that the pores are closed. It can open the pores, cause mild sweating and expel Wind and Cold. Roasted Jing Jie is less pungent because processing has reduced the taste. If the pores are open, sweating is present, or the patient has an aversion to wind instead of cold; this indicates that it is not necessary to open the pores, so roasted Jing Jie is then more suitable.

Jing Jie Tan is able to stop bleeding and it is used in bleeding conditions. When Jing Jie is roasted to charcoal, its pungent property is reduced, but an astringent property emerges. It can stabilize the Blood and stop bleeding. Meanwhile, it can also expel Wind and calm the Blood, therefore stopping bleeding.

‘ Xiang’ means ‘aroma’, ‘fragrance’; ‘ Ru’ means ‘gentle’. As the name explains, this herb is pungent and slightly warm with an aromatic smell. It enters the Spleen, Stomach and Lung meridians. Xiang Ru can, on the one hand, disperse Wind and Cold, induce sweating and release the Exterior; on the other hand, it transforms Dampness and harmonizes the Spleen and Stomach. The functions are similar to that of Ma Huang, but gentler. It is often used in summer when the weather is warm, the Wind-Cold is not so strong, the pores are not closed so tightly as in winter and the mild Wind-Cold attacks the body and causes an Exterior Wind-Cold syndrome. Meanwhile, Xiang Ru is used to treat abdominal pain, vomiting and diarrhea in summer, if overconsumption of cold drinks has injured the Stomach and Spleen, such as in acute gastritis.