Causes of Disease

There are 4 main categories that cause disease:

1. Things that come from outside the body (like heat, wind, cold, damp, buses, karate kicks etc)
2. Things that arise from inside the body 
3. Miscellaneous causes, whose origins are neither inside or outside
4. Phlegm  

Isn't it lovely that snot has it's own category? 

But I digress...

The bottom line is that there are many forces inside the body, that when in harmonious balance, keep the body in good health.  When this balance is upset, disease develops.

Development of disease depends on two factors:

1. The immunity level of the body
2. The strength of the disease pathogen

If the body is in strong health, then there is no way that disease can get a foothold, and it will remain only on the exterior Qi for short periods of time.  Because of this fact, much of Chinese medicine is prevention based, promotes general health, and correcting of imbalances early in their genesis to keep the patient healthy.

The Qi, blood and organs and their functions when operating in healthy parameters are considered Normal Qi.  Disease is seen a battle between the Normal Qi and the pathogenic factors.

The Six Excesses

1. Wind
2. Cold
3. Heat
4. Dampness
5. Dryness
6. Summer Heat (Fire)

The term excess means "Abnormal, Evil, or Pernicious Influence".  When normal environmental forces become excessive (hot spell in winter, cold spell in summer), they can easily affect the individual, if their normal Qi is out of balance.

Differentiations between the excesses is made on a basis of symptoms, not tests aimed at discovering the precisely defined disease-causing agent.  This means the disease is described in terms of the bodies' response to it.  In this way, the same Western defined disease that exists in two or three people can manifest in two or three or more different ways, and thus each will have a different Chinese diagnosis.

Symptoms of excesses (except Fire) are defined with a particular season and a yin or yang predominance.  

Wind (Spring Yang)

Disease caused by wind will arise quickly and change their symptoms quickly.  Common symptoms include muscle spasm, vertigo, pruritus or a pain that changes location.  Wind diseases of an exogenous origin will usually affect the skin, head, pharynx and lungs first.

Wind is capable of carrying the other excesses into the interior of the body.

Internally, when Liver yang is hyperactive, dizziness and convulsions occur, and high fever symptoms can occur as well.  Both are caused by the Wind travelling to the interior of the body.

Cold (Winter Yin)

The main symptom of this excess is the whole body or part feels cold.  Cold congeals fluids, which causes pain.  Pain comes from the obstruction in the flow of Qi and blood.  Cold causes material substances to coagulate in the channels, which will cause cramps and spasms.  

In cold diseases, the body excretions (mucus, tears, phlegm, urine and stools) are white or clear and watery.

When the Yang is weak, symptoms of cold may appear, but it will be symptoms of empty cold.

Heat or Fire (Yang)

The main symptom of this excess is the whole body or part feels hot!  Heat easily injures and dries up the bodies' fluids.  Thus, the tongue and stools become dry and thirst will be present.  Heat can cause the blood to travel outside the channels, causing hemorrhage or rashes.

In heat diseases, body excretions are dark or yellow and foul smelling.  Sometimes, the act of expelling will leave a sensation of heat in that area.  

Often, diseases caused by other excesses in the body will transform into heat within the body. 

Dampness (Long Summer Yin)

Keep in mind that the seasonal references are for the Chinese seasons.  It states in the Ni Jing that the practitioner must become familiar with his or her local climate.

This excess often happens during prolonged contact with damp weather or humidity.  Dampness is sluggish and stagnating.  Diseases caused by this take a long time to be cured.  When dampness is on the external body, the patient will feel anxious, limbs will feel heavy and the head feels swollen.  

When dampness invades the muscles and joints, all movements become painful, and affected areas will have edema.

Dampness tends to attack the spleen.  Interior dampness comes when the spleen's transforming and transporting functions become weak.

Damp diseases during the winter are likely to be very serious.

Dryness (Autumn Yang)

Dryness attacks the fluids of the body and can result in dry skin, chapped lips, hacking cough and constipation.

Similar symptoms can occur if the body's Yin substances are seriously depleted (such as from a long febrile disease). 

Summer Heat (Summer Yang)

Primary characteristic is fever with pronounced sweating.  This injures the Yin of the body and Qi.  Dampness almost always accompanies this excess.

Seven Emotions

They are:

1. Excessive happiness (Fire)
2. Anger (Wood)
3. Worry (Metal)
4. Pensiveness (Earth)
5. Sadness (Metal)
6. Fear (Water)
7. Anxiety (Water)

In addition, frustration upsets the free-flowing nature of the Liver, and often leads to anger.

These normal emotions can lead to disease if they are sustained for a long period of time, and can upset the organ associated with the element of each emotion, which in turn, upsets the yin-yang balance in the body.

While emotion related diseases may be described as psychosomatic in Western terms, in Chinese medicine, they are internal imbalances.

Other Causes Neither Outside or Inside in Origin

These are for the most part, lifestyle choices.  For instance, inconsistency in quantity, quality and timing of eating and drinking often causes digestion disorders.  Overeating of hot or cold foods can also lead to digestion distress.  Overeating of the 5 flavors can injure the corresponding organ.

Sexual activity and reproductive organs are linked to the Kidneys in men, and Kidneys and Liver for women.  Too much or too little activity can weaken the corresponding organs.  Too many births for a woman can damage the Ren channel and greatly affect menstruation.

Too much or too little manual labor can also damage the body.  

Moderation is the rule of the day to keep these other causes from affecting the body.

Phlegm

The Chinese concept of Phlegm is not simply what the lungs will cough up in disease, but also to stagnant fluids in the body.  Traditionally, it's formation is due to the spleens inability to transform and transport fluids properly.  Therefore, the spleen is the source of phlegm.

The concept of phlegm also includes disorders that Western medicine would call endocrine, metabolic, enzymatic and other biochemical disorders.

When water in the body becomes stagnant, it forms phlegm.  

There are many reasons for stagnation, but the most common causes are deficient Qi and excess heat.

Phlegm is both a cause and result of disease.

When it collects in the lungs, there is coughing, wheezing and profuse expectoration.

When it collects in the stomach, there is nausea and vomiting.

When it invades the channels, there is local swelling.

When it surrounds the heart, delirium ensues.

In practice, the various causes of disease often overlap one another and can occur together.  Diagnosis is directed at determining the relationships which exist at a particular time between the disease causing factors and their effects on the Organs, Channels and Tissues.