Stage 1 of COPD
The lungs are sensitive to smoke and pollution and easily become dry when exposed to fine lung qi tonic herbalparticles in the air; this is referred to as Lung Yin Deficiency. With Lung Yin Deficiency, a dry cough develops and symptoms such as hoarseness and a dry scratchy throat appear from time to time. Another possibile initial stage cause of COPD results from chronic inflammation caused by asthma; this results in a remodeling of the airways with a narrowing and hardening of the bronchial tissue.

Stage 2 of COPD
Left untreated, the Yin of the Lungs becomes more depleted and the Lung Yin Vacuity signs intensify; the dry cough begins to produce sticky sputum that becomes tinged with blood and insomnia likely develops. Yin correlates with substance and tissue in the body, so as Lung Yin Deficiency worsens the air sacs begin to lose their elastic quality and the walls between the air sacks are destroyed as lung spasms and inflammation develop. During this stage, breathing becomes noticeably more labored.

Stage 3 of COPD
As Lung Yin Deficiency progresses and heat builds in the lungs, the lungs begin to Liver-fire-herbalcompensate by producing Phlegm-Fluids. The phlegm is often sticky with color and begins to obstruct the free flow of Qi in the Lungs. Because the phlegm is condensing due to the Heat in the Lungs, medicines and herbs that are extremely drying will cause further complications and should be avoided.

Stage 4 of COPD
With the phlegm obstructing the lungs, Lung Qi Deficiency develops, breathing becomes labored, and there is extreme fatigue. The Lungs control the opening and closing of pores, so spontaneous perspiration is common with Lung Qi Deficiency.