Cold as a pathogenic factor in Chinese Medicine

Cold, a Yin phenomenon, causes feelings of coldness and a slowing of circulation and all metabolic functions. There is a tendency towards cold extremities, to wear more clothes regardless of the weather, and in general, to contract and hunch over to minimize body surface and maintain inner warmth.

Upon examination, the body, or parts of it, feel cold to the touch and have a generally pale appearance, which in some cases can also be an indication of  Blood Deficiency. Any bodily secretions are clear or white in color, such as clear or white mucus, sputum, vomit, urine, diarrhea or vaginal discharges. Cold is aggravated during colder climates and the season of Winter. It can, however, become an issue any time of year with exposure to Cold.

Just as water turns to ice when exposed to coldness, Cold in the body constricts, contracts and congeals. This causes physical obstructions, blocking the flow of Qi and Blood in the body and often causing various kinds of pain, contraction, spasm, cramps and stiffness. Usually the symptoms can be eased when applying Heat. 

When Cold stays in the skin and muscles, it contracts the pores and Stagnates the immune system's defensive energy (Wei Qi). When this occurs, External Cold invades, resulting in fever, strong chills, a lack of sweating, body aches and an aversion to cold. If Cold remains in the muscles and Channels, numbness, rigidity and coldness can occur.

Being Yin in nature, Cold in excess can injure the body's Yang Qi and cause symptoms of Yang Deficiency. External Cold comes on quickly and impairs the Defensive Yang of the body. When this occurs, chills are more pronounced than fever and there is little, if any, sweating. Cold Evil can also invade and injure the Yang function of the Organs. For example, Cold Evil can attack the Intestines and Stomach, causing a stomach ache and watery diarrhea containing undigested food or vomiting of water.

Cold can also arise Internally from an overall lowering of metabolism or insufficiency of Yang. Internal Cold is usually chronic and is characterized by coldness, slowness and hypo-activity of the Organs and metabolism. Yang then may be unable to warm and nourish the limbs, digest food or assimilate and transport Body Fluids and nutrients. Internal Cold is most often related to the Kidneys since they are the root of the body's Yin and Yang, and the throne of the Gate of Fire (Ming Men). If there is Internal Coldness, the body becomes more susceptible to External Cold invading the body.

Causes of Cold include improper dressing for the season or environment such as seasonal changes; living in cold places; excess eating of foods and drinks with a cold temperature, cold energy or eliminating nature, such as raw foods, fruits, juices, ice cream, popsicles and iced drinks; inactivity; and lack of exercise.

The characteristics of Cold

Cold injures Yang

Cold, whether Exterior or Interior, tends to injure Yang: the Spleen and the Kidneys are usually the first Organs to be affected by Cold.

Cold congeals Blood

Cold congeals Blood and it is therefore a major cause of Blood Stagnation. When Blood Stagnates, there is intense pain: when the Stagnation derives from Cold, the pain is accompanied by chilliness, it is aggravated by cold and it is alleviated by the application of Heat. 

Blood Stagnation in the Uterus due to Cold is a very common example of Cold congealing Blood: it results in painful periods with small, dark clots.

Cold contracts tissues

Cold contracts tissues (muscles, sinews, blood vessels, skin). As Cold causes contraction, contraction of muscles and sinews by Cold causes stiffness and pain.

Cold causes clear discharges

Cold is often manifested with thin, watery and clear Body Fluid discharges, such as a clear white discharge from the nose, very pale urine, watery loose stools and clear watery vaginal discharges.

Cold pertains to the Kidneys

In the scheme of correspondences among Organs, seasons and climates, Cold pertains to Winter and to the Kidneys. This means that Cold is obviously more prevalent in Winter and that it has a strong tendency to injure the Kidneys (specifically Kidney Yang).

However, it should be pointed out that Cold can occur in any season and that it injures other Organs besides the Kidneys.

External Cold

Invasion of External Cold in the Lungs

This corresponds to an invasion of Wind Cold which details are explained in the page on Wind.

Invasion of the Channels and joints by Cold

When Cold invades the Channels and settles in the joints it causes Cold Painful Obstruction Syndrome (Bi Syndrome). This is characterized by intense pain, often in a single joint. The pain is aggravated by exposure to cold and alleviated by the application of Heat.

Invasion of the muscles and sinews by Cold

External Cold can invade the muscles and sinews, causing local pain and stiffness. This is a very common occurrence in the muscles of the shoulders and neck. For example, a very stiff, locked neck with a sudden onset is often due to Cold in the muscles of the neck.

Invasion of external Cold in Stomach, Intestines and Uterus

External Cold can invade three Organs directly: these are the Stomach (causing epigastric pain and vomiting), the Intestines (causing abdominal pain and diarrhoea) and the Uterus (causing acute painful menstruation).

In all these three cases the symptoms are accompanied by chilliness and the pain is aggravated by cold and alleviated by the application of Heat.

Please note that although this Cold is of external origin, once in these three Organs, it is internal Cold.

Internal Cold

Interior Cold can be in Excess (Full) or Deficient (Empty). Interior Full Cold originates from Exterior Cold, which may be either Wind Cold or Cold invading certain Organs directly. In either case, if the Exterior Cold penetrates in the Interior and in the Internal Organs, it becomes Interior Full Cold.

Full Cold 

The main symptoms of Full Cold are: feeling cold, cold limbs, thin clear discharges, severe pain, aggravation of pain from pressure, aggravation from cold and alleviation from application of Heat, desire for warm drinks, no thirst, bright white complexion, thick, white tongue coating and Slow-Full-Tight pulse.

Generally speaking, Interior Full Cold can last only a relatively short time. After prolonged retention, Interior Cold consumes Yang (often of the Spleen first), giving rise to Empty Cold. Thus a Full Cold pattern can turn into an Empty Cold one.

Empty Cold

The main symptoms of Empty Cold are: Feeling cold, cold limbs, Thin clear discharges, dull pain, amelioration of pain from pressure, aggravation from cold and alleviation from application of heat, desire for warm drinks, no thirst, dull white complexion, thin, white tongue coating, pale tongue body and Slow-Weak pulse.

Internal Empty Cold arises from Deficiency of Yang, usually of the Spleen, Lungs or Kidneys. In this case the Cold does not come from the Exterior, but is internally generated by Yang Deficiency.

Empty Cold may also derive from the transformation of Full Cold: in fact, Full Cold cannot last a long time as Cold injures Yang and therefore after some time it will induce a Yang Deficiency. When that happens, Full Cold changes into Empty Cold.

Apart from the general manifestations outlined above, other symptoms vary according to which Organ is mostly affected. The Heart, Lungs, Spleen, Stomach and Kidneys can suffer from Yang Deficiency and Interior Cold.

The symptoms of Heart Yang Deficiency (in addition to the above-mentioned general symptoms) with Interior Cold are stuffiness and pain in the chest, purple lips and a Knotted pulse. In Lungs Yang Deficiency there is a propensity to catch colds and a cough with white mucus. In Spleen Yang Deficiency there is diarrhoea or loose stools with some abdominal pain. In Kidneys Yang Deficiency there is frequent, pale and profuse urination, lower backache, cold feet and knees and impotence in men or white leucorrhoea in women.