Part of the brilliance and deep reaching clinical efficacy of Chinese medicine is its ability to make seemingly difficult and confusing conditions clear and accessible. One example is the understanding of the different origins of tan/phlegm.

In our modern discussion, we often emphasize  phlegm as coming from pathology of the Spleen as it is associated with the Earth phase and the climatic influence of dampness. And while the Spleen and Earth can be a cause of dampness all five phases can also be involved and there are seven different types of phlegm. Interestingly, in the long history of Chinese medicine there is no major tradition that emphasizes phlegm as the root cause of disease. In other words, it’s understood that phlegm is a branch issue that is responding to other deeper pathology.

The Five Phases and Seven Types of Phlegm

• Damp Phlegm/Earth: Associated with the Spleen, this is what we often currently associate with dampness. Damp phlegm can both come from--and contribute to-- weakness in the digestive system (Stomach/Spleen) and affect day-to-day energy through its weaking of the creation of post-natal Qi. Treatment strategies include transforming and expelling phlegm.
• Dry Phlegm/Metal: Associated with the Lung, this is phlegm that occurs as the body’s response to a lack of healthy fluids. As result, the Lung and the body in general can create or hold on to thicker fluids because thinner, less viscus  ones are not available. As the Lung is also associated with the creation of post-natal Qi, dry phlegm can also create weakness and tiredness. Unlike with damp phlegm above which focuses on drying, the treatment strategy here is to moisten.
• Cold Phlegm/Water: This is where the fluids can become thicker and heavier from the congealing presence of cold. And with its association with the Kidney, cold phlegm can both come from--and contribute to-- issue of Yuan/Source Qi. The treatment strategies include clearing cold and tonfiying Kidney Yang.
• Fluid Phlegm/Water: Also associated with the Kidney. Fluid phlegm occurs when the phlegm in the middle burner descends into the lower burner and begins to affect the Kidney and Yuan/Source Qi. A way to differentiate fluid phlegm from cold is that in this case their may be the accumulation of fluids and edema in the lower part of the body. As with cold phlegm above, the treatment strategies include clearing cold and tonfiying Kidney Yang.
• Wind Phlegm/Wood: An interesting and important type of phlegm to understand in several seemingly hard to treat diagnoses  including a wide range of neurological conditions and late-stage Lyme. Wind is an excess of Yang in the Liver and tends to go upward and phlegm is an excess of Yin which tends to descend. Understanding that the directionality of wind and phlegm can be responding to each other--including as a response to create balance—can be relevant clinically and important in understanding that one imbalance can create others. The treatment strategy includes subduing wind.
• Hot Phlegm/Fire: Hot phlegm can occur in the Heart and other organs (particularly the Stomach)  and can appear as the body attempts to use the cooling and heavy nature of the Yin of phlegm to control the ascending and warm nature of Yang and fire. As heat can also cause dryness, hot phlegm and dry phlegm can occur simultaneously and sometimes in the same organ. The treatment strategies are to clear heat and tonify Yin.
• Insubstantial Phlegm/Fire:  Associated with the Heart, insubstantial phlegm is used to describe a condition where--based on signs and symptoms or disease progression—phlegm should be present but is not found diagnostically. As the treatment principles to address the condition are  associated with the Heart--including the idea of vaporizing phlegm--much of focus on treating insubstantial phlegm relates to the upper burner.