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Lung Cancer : Causes
Western Medicine Chinese Medicine
Tobacco smoking causes more than 75% of lung cancer cases. Some researchers put that figure as high as 95 percent. People who started smoking as teenagers have the greatest risk of developing lung cancer. Lung cancer is most commonly seen in adults aged 40-70 who have smoked cigarettes for about 20 years.
Second-hand tobacco smoke, which is the smoke breathed in by people sharing an indoor environment with smokers, also called environmental tobacco smoke, is believed to contribute to the development of lung cancer. Children exposed to second-hand smoke are thought to be particularly in danger of developing a variety of respiratory diseases, including lung cancer, later in life.
Occupational exposure to asbestos is associated with a particular type of lung cancer called mesothelioma. Other occupational exposures associated with lung cancer include contact with the processing of steel, nickel, chrome and coal gas.
Exposure to radiation raises the risk of developing cancers of all kinds, including lung cancer. In areas where radon gas levels are high, (i.e. Hong Kong), poor ventilation may lead to high exposure among people spending long hours indoors. Miners of uranium, fluorspar may also be exposed to radiation by breathing air contaminated with radon gas.
Air pollution: The risk posed by air pollution and its possible links to lung cancer are controversial. There are more cases of lung cancer among city dwellers than among those living in rural areas, even after the effects of smoking are ruled out as the cause. However, because the components of air pollution are so complex and variable it is hard to prove whether or not air pollution causes lung cancer.


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Retention of Wetness and Phlegm evil Hypofunction (under functioning) of the spleen causes a disturbance in body-fluid metabolism and failure of fluid transportation, which are part of this organ's main functions in TCM. Untransformed body fluid turns into phlegm and wetness, which are toxic materials. These toxic materials flow upward and interfere lung function.

Stagnation of Vital Energy
Under normal conditions, the vital energy (qi) circulates smoothly in and out, up and down and all over the body. If an internal injury occurred, for example, depression of the seven emotions will cause deficiency and impairment of vital qi and derangement of yin and yang, it may cause breathing syndromes due to the improper lung function. TCM believes yin and yang disharmony is the cause of disease and physiological disorders. Disharmony means the proportions of yin and yang are unequal and unbalanced. When one aspect is deficient, the other is in excess. Lung cancer is induced by an overall deficiency of qi and yin in the body, which leads to an excess syndrome in the lungs. The excess syndrome generally manifests as pathological lung changes such as a stagnation of qi flow, blood stasis (lack of easy blood flow) and accumulation of phlegm and toxins.

Blood Stasis
Vital energy (qi) acts as the commander of blood. It means that vital energy is the motivating force of the blood circulation. Therefore blood stasis is usually accompanied by stagnation of vital energy. Coagulation and stagnation of qi and blood flow can contribute to the formation of a tumour.

Pathogenic evils (substances causing disease) invade the lung
When the healthy energy is deficient due to body dysfunction or structural damage. Some pathogenic evils such as wind and cold take advantage of this imbalance and invade the lung. Over time these evils accumulate in the lungs and can cause cancer.

How do these factors contribute to the development of lung cancer?
As a result of lung dysfunction and improper qi flow, body fluids cannot be properly distributed. They begin to accumulate in the lungs and eventually turn into phlegm. Over time, the phlegm, stagnant blood and qi flow, and the remaining toxins trapped in the lungs form into a lump, which would be known in western medicine as a lung cancer mass.

Other Factors Associated with the Development of Lung Cancer:

1. Smoking
2. Occupational Exposure to Carcinogens
(substances that can cause cancer) i.e. inorganic arsenic, asbestos, chrome, nickel, radon, hydrocarbon in coal smoke, coal tar, and fossil oil
3. Air pollution
4. Ionizing Radiation
5. Diet and Nutrition