1. Exterior Clearing

     These herbs expel and clear external pathogenic factors in the superficial region of the body. Generally they are pungent in flavour.
    External pathogenic factors usually include a Wind component as Wind can penetrate the Wei Qi and block the usual flow of energy at the most external level- the TaiYang level. The Tai Yang level corresponds to the Bladder and Gall Bladder channels which cover the back of the neck. The external pathogenic factors invade beneath the skin causing exterior symptoms, such as stiff neck, chills and fever, headaches and general muscle aches. The chills and fever and headaches are a sign of the battle raging as the body defends itself. The muscle pain in other parts of the body are caused by sluggish circulation as the body draws energy from other regions. Or locally as a direct consequence of the pathogens blocking circulation. .
    The functions of the Lungs include control of Wei Qi and the pores of the skin. It's action is said to be a dispersing action. When this dispersing action is impaired, it can be cleared by diaphoretic action. As the pores are opened energy is pushed through, clearing the superficial region of pathogenic factors and then reinforcing the Wei Qi.   The action tends to radiate Yang Qi (Wei Qi is mostly composed of Yang Qi) and reinforce the Wei Qi which has the effect of breaking external energy attachments, centering the person quite well and flushing out the lymphatic/digestion/sinous phlegm which has accumulated though the external attachment.
   Internal pathogenic factors residing just beneath the skin and in the musculoskeletal system are also treated using exterior clearing herbs. These herbs open the pores and promote eruptions, allowing the pathogens to excape. eg Heat rashes,  Summer Heat eruptions
Athralgic Wind Dampness is also treated with exterior clearing herbs.

    Some of the herbs also have the effect of promoting the descending function of the Lung, relieving cough and asthma, and benefiting the Lung Qi action of dispersing to treat cough or dyspena.  Often they induce diuresis to reduce edema. Some also treat internal conditions such as arthalgic Wind Dampness which is vented through the pores.

     According to their properties, diaphoretics are divided into two groups - Warm and Cool in nature.  The dosage of this class of drugs should be just the right amount and as soon as the patient's condition is better, diaphoretics should be discontinued. Otherwise, excessive sweating may lead to consumption of Yang Qi and impairment of the body fluid.
For Exterior deficiency syndrome with spontaneous seating, fever due to Yin xu, consumption of deficiency of the body fluid in the later stage of febrile diseases, and for bleeding, chronic suppurative infection on the skin such as sores, carbuncles, and stranguria, diaphoretics should be used cautiously or avoided altogether. Most these drugs have an aromatic constituents. So to prevent decrease in efficacy, long period of boiling should be avoided.

Exterior Clearing - Warming


Herbs of this kind have strong dispersing actions, chiefly for dispersing Wind Cold. They are indicated for exterior syndromes due to affection by Wind cold exopathogens with aversion to cold, slight fever, headache, body and neck pains, absence of thirst, thin and white coating on the tongue, and floating and tense pulse. Some of these herbs can be used for cough due to Wind Cold, arthralgia due to Wind Cold Dampness, and edema accompanied by exterior syndromes.

Exterior Cooling


Herbs of this kind usually have pungent or bitter flavours and Cold or Cool properties. Their diaphoretic action is comparately mild and they are mainly used for expelling pathogenic Wind Heat. These drugs are indicated for Exterior syndrome due to affection by Wind Heat exopathogens with synptoms and signs of high fever with slight aversion to Cold, thirst with or without Heat, white thin dry coating on the tongue, floating and rapid pulse, etc. Some of these Herbs can by used for the treatment of measles. In clinical practice, they are usually used in combination with Heat clearing Herbs.