In Ayurvedic theory, breath is associated with vital energy, which can be strengthened by exercise and breathing. In Chinese, tradition Qigong is used in a similar way to strengthen energy levels through better breath control. Therefore, as you can see from the linik, the Chinese belief that the "lungs control Qi" seems quite logical.
Qi is subdivided into many different categories and the lungs are particularly associated with "defence Qi" (Wei Qi), which they help to send to the body's surface to repel invading evils. 醫(yī)學.全.在線.網.站.提供
The lung Qi tends to move downwards. Therefore, it encourages the flow of water and fluids (known as "Jin Ye" in Chinese) through the system to the kidney and urinary bladder - lung problems are thus often blamed for oedema and fluid retention in Chinese medicine.
Logically, the lungs are also connected with the nose - anatomically at the end of the respiratory tract - and also with the sense of smell, while the connection with Wei Qi and surface energies highlights the view that the lungs are "seen in the skin and body hair" - healthy, glowing skin indicates strong lung Qi.
As with the other Zang organs, the lungs also have a spiritual aspect. In this case it is "Po" (known as "vitality" in Chinese - which is associated more with the physical side of concentration rather than thought processes).
If the large intestine fails to reabsorb sufficient moisture, the stools will be watery and one will have diarrhoea.
Blockages in the large intestine - as in constipation - are believed to interfere with the descending function of lung Qi