Traditional Chinese Medicine (TCM) holds that "all the Zang-fu organs can cause a cough, not just the Lungs," and that "exposure to cold and the consumption of cold drinks can injure the Lungs." This tells us that while most coughs are caused by lung disorders that lead to the stagnation and counterflow of Lung Qi, the consumption of cold and raw foods can also harm the Spleen and Stomach, leading to a decline in Spleen function. This results in the accumulation of dampness, which generates phlegm, affecting the Lungs and thereby triggering a cough. This is what TCM refers to as "the Spleen is the source of phlegm, while the Lungs are the vessel that stores it."
Therefore, Tian Zhengjian reminds us that individuals with a cough should pay attention to their diet. Those with a deficiency of Lung Yang should avoid consuming excessively cold foods. For instance, patients with chronic bronchitis should be cautious about consuming "cold-natured" foods. Excessive consumption of watermelon, banana, snow pear, pomelo, orange, persimmon, or cooling herbal teas can lead to an imbalance between Yin and Yang, causing a deficiency of Yang and triggering a cough. It is worth noting that some believe snow pear moistens the Lungs and can stop a cough, but this is not always the case. Snow pear is only suitable for relieving coughs caused by Lung Heat; patients with Lung deficiency should avoid it, as it can worsen the cough. Furthermore, children have weaker digestive systems and should strictly avoid cold foods to prevent exacerbating the condition and prolonging its duration. Conversely, for patients with a cough, appropriate dietary conditioning can often lead to twice the result with half the effort.