The Six Excesses (Liù Yín) is a term in Traditional Chinese Medicine (TCM) that refers to the six types of external pathogenic factors: Wind, Cold, Heat, Dampness, Dryness, and Fire. Below are their concepts and pathogenic characteristics:
Concept
The Six Excesses originally refer to six different climatic changes in nature, which under normal circumstances are called the “Six Qi” (Liù Qì), serving as conditions for the growth of all things, and the human body can adapt to them. However, when climatic changes are abnormal, exceeding the body’s ability to adapt, or when the body’s righteous Qi (Zhèng Qì) is insufficient and resistance decreases, the Six Qi can become pathogenic factors that invade the body and cause disease. At this point, the Six Qi are referred to as the “Six Excesses”.
Pathogenic Characteristics
– Wind Pathogen (Fēng Xié): Wind is a Yang pathogen, characterized by its ability to disperse and invade Yang positions, often causing the pores to loosen and open, leading to symptoms such as headaches and nasal congestion. The Wind pathogen is known for its rapid movement and variability, causing migratory pain in joints, and its onset is swift and unpredictable. Wind is also known as the leader of all diseases, often combining with other pathogens such as Wind-Cold and Wind-Heat.
– Cold Pathogen (Hán Xié): Cold is a Yin pathogen that can injure Yang Qi. For instance, when external Cold invades the skin, it can obstruct the defensive Yang, leading to symptoms of aversion to cold. If it penetrates the spleen and stomach, it can damage Spleen Yang, resulting in abdominal cold pain. Cold has a stagnating nature, easily causing Qi and Blood to congeal and obstruct, leading to pain symptoms. Cold can also constrict the Qi mechanism, causing the pores, meridians, and tendons to contract and spasm, as seen when Cold invades the meridians and joints, leading to difficulty in limb movement.
– Heat Pathogen (Shǔ Xié): Heat is a Yang pathogen, characterized by its hot nature, often manifesting as high fever, irritability, and a flushed face. Heat tends to rise and disperse, easily injuring fluids and consuming Qi, leading to symptoms such as thirst and shortness of breath. Heat often accompanies Dampness, presenting with symptoms of fatigue in the limbs, chest oppression, nausea, and loose stools due to Damp obstruction.
– Damp Pathogen (Shī Xié): Dampness is a Yin pathogen that can obstruct the Qi mechanism and damage Yang Qi, leading to dysfunction in the spleen and stomach, resulting in symptoms such as chest oppression and poor appetite. Dampness is heavy and turbid, causing symptoms characterized by heaviness and filth, such as a heavy head, a feeling of heaviness throughout the body, and cloudy urine. Dampness is sticky, leading to symptoms that feel sticky and uncomfortable, such as sticky stools and a greasy tongue coating; the condition can be chronic and prone to recurrence. Dampness tends to descend, often affecting the lower body, leading to symptoms such as lower limb edema, turbid urination, and leukorrhea.
– Dryness Pathogen (Zào Xié): Dryness is characterized by its dry and astringent nature, easily injuring body fluids, leading to symptoms such as dryness of the mouth and nose, dry throat, and dry skin. Dryness can harm the lungs, which are delicate organs that prefer moisture and dislike dryness; when the Dryness pathogen invades the lungs, it can lead to dry cough with little phlegm and difficulty expectorating.
– Fire Pathogen (Huǒ Xié): Fire is a Yang pathogen, characterized by its tendency to rise and cause disease, often manifesting in the upper body with symptoms such as a red face, red eyes, and sores on the tongue. Fire can easily injure fluids and consume Qi, leading to fluid depletion and Qi loss. Fire pathogens can also generate Wind and move Blood, leading to convulsions; they can force Blood to move erratically, causing various types of bleeding. Fire pathogens can also lead to swelling and abscesses, causing local Qi and Blood stagnation, with excessive heat leading to tissue necrosis and the formation of boils and sores.